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Using fungicides or combinations of fungicides to provide mold and decay fungal protection to OSB Choi, Baek Yong 2008

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USING FUNGICIDES OR COMBINATIONS OF FUNGICDES TO PROVIDE MOLD AND DECAY FUNGAL PROTECTION TO OSB  by  BaekYong Choi  B.Sc., Kookmin University, 2004  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE  in  THE FACULTY OF GRADUATE STUDIES (FORESTRY)  THE UNIVERSITY OF BRITISH COLUMBIA  January, 2008 ©BaekYong Choi, 2008  Abstract The use of wood-based composites has increased dramatically over the last two decades due to a number of factors. One reason is that Oriented Strand Board (OSB) is being increasingly utilized in residential applications in place of plywood. However, the use of OSB in residential construction is often limited because of its susceptibility to attack by biological pathogens such as mold and decay fungi. The environmental conditions that exist in certain use categories can be so adverse that the performance of these composites is negatively affected. This study was divided into two parts. The first phase examined the effectiveness of fungicides or combinations of fungicides (including some metal-containing preservatives) for enhancing the mold resistance of strandboard. During the second part of the study, preliminary experiments investigated the effectiveness of fungicides or combinations of fungicides using an agar-block test to estimate the preservative toxic threshold retention. The compatibility of the fungicide on the resin curing was studied by measuring change in the resin gelation and viscosity. After these screening experiments were completed, large size boards were prepared and mechanical and decay resistance properties were examined. It was found that mold and decay resistance properties of strandboard directly were related with the biocide type and its concentration. Greater protection of the strandboard was achieved with an increase in preservative retention levels. However, due to the relatively high cost of non-metallic (organic) preservatives, it is important to find the minimum amount of preservative that can protect the OSB against mold and decay fungi. One method of reducing the cost and increasing efficacy is to combine different fungicides to determine whether synergism exists. Even if synergism does not occur, it may reduce the overall cost by combining a less expensive biocide with a smaller amount of a more expensive biocide where their biocidal efficacy complements each other. In addition, it is important to understand that high retention of preservative may also cause ii  negative effects on the mechanical properties of strandboard. This maybe noticeable of the high retention level of the biocide when a greater negative effect on the internal bonding (IB) strength may be recorded. Lower IB strength for treated strandboard may be attributed to the formulation of chemical residue in the wood surface, which may interfere with the reaction between wood and phenol formaldehyde (PF) resin. Surface-active agents in the preservative may also cause the PF resin to over-penetrate into wood decreasing bond strength. Increasing moisture content of strands by the introduction of an emulsified aqueous biocide solution, may cause dilution of the resin, and reduced bonding. It should also be noted that high retention of preservative which cause a change in the viscosity and gelation time of PF resins would be problematic for the operation of an OSB plant. For viscosity change, it could significantly affect the flow properties of the resin on the wood furnish and its atomization as it is spraying onto the wood furnish. In addition, it may require further modification to the equipment that supplies the resin to the spray nozzle. For changes in the gelation time, this may require changes to the press time at the OSB plant.  iii  TABLE OF CONTENTS ABSTRACT  ^ii  TABLE OF CONTENTS  ^iv  LIST OF TABLES  ^vii  LIST OF FIGURES  ^viii  LIST OF ABBREVIATIONS ^ ACKNOWLEDGEMENTS  ^xi  CHAPTER 1 Background  ^1  1.1. Introduction  ^1  1.2. Objectives  ^4  1.3. Outline of thesis  ^5  CHAPTER 2 Literature review: Protecting wood composite products  ^6  2.1. Oriented strandboard  ^6  2.2. Problems of OSB as structural panels  ^7  2.3. Applying OSB protection  ^8  2.4. Wood preservative used for timber in residential construction  ^10  CHAPTER 3 The evaluation of fungicides or combinations of fungicides for protection OSB against mold growth 3.1. Introduction  ^14 ^14  3.2. Materials and Methods  ^15  3.2.2. Preservatives  ^15 ^18  3.2.3. Formulation preparation  ^18  3.2.4. Sample preparation  ^19  3.2.5. Preparation of mold inoculum  ^21  3.2.6. Addition of samples to the mold chamber  ^22  3.2.7. Mold growth rate system  ^23  3.2.8. Statistical analysis  ^24  3.2.1. Wood  3.3. Results and Discussion  ^25  3.3.1. Mold resistance properties  ^25  3.3.2. Evaluation of mold growth in every week  ^30  3.4. Conclusions  ^33  CHAPTER 4 Estimation of fungicides or combinations of fungicides toxic threshold retention from laboratory decay test  ^34  4.1. Introduction  ^34  4.2. Materials and Methods  ^35 iv  4.2.1. Wood 4.2.2. Preservatives 4.2.3. Preparation of decay inoculum 4.2.4. Formulation and sample preparation 4.3 Results and Discussion 4.3.1. The first screening trial 4.3.2. The second screening trial 4.4. Conclusion  ^35 ^35 ^36 ^37 ^41 ^41 ^45 ^48  CHAPTER 5 The influence of selected fungicides or combinations of fungicides on gelation time and viscosity of PF resin for OSB  ^49  5.1. Introduction 5.2. Materials and Methods 5.2.1. Wood preservative and resin 5.2.2. Preparation of formulation 5.2.3. Rheological measurement 5.2.4. Physical measurement 5.3. Results and Discussion 5.3.1. Viscosity and gelation time 5.4. Conclusion  ^49 ^52 ^52 ^53 ^53 ^54 ^56 ^56 ^65  CHAPTER 6 The effect of fungicides or combinations of fungicides on mechanical properties of OSB  ^66  6.1. Introduction 6.2. Materials and Methods 6.2.1. Panel manufacture 6.2.2. Mechanical properties study 6.2.3. Statistic analysis 6.3. Results and Discussion 6.3.1. Static bending properties 6.3.2. Internal bond (IB) properties 6.4. Conclusion  ^66 ^68 ^68 ^70 ^72 ^73 ^74 ^79 ^83  CHAPTER 7 Decay resistance properties of OSB produced from strands pretreated with fungicides or combinations of fungicides ^84  7.1. Introduction 7.2. Materials and Methods 7.2.1. Wood and decay fungi preparation 7.2.2. Decay resistance study 7.2.3. Statistic analysis 7.3. Results and Discussion  ^84 ^86 ^86 ^86 ^87 ^89  v  7.3.1. Decay resistance properties  ^89  7.3.2. Estimation of biocide toxic threshold retention 7.4. Conclusion  ^97 ^102  CHAPTER 8 Summary and Conclusions  ^103  Chapter 9 Recommendations  ^108  References  ^109  Appendix A  ^117  Appendix B  ^121  Appendix C Appendix D  ^123 ^124  Appendix E  ^132  vi  LIST OF TABLES Table 2.1^Wood composites and Preservative treatments  ^9 Table 3.1^The detailed sample identification for chemical treatment ^17 Table 3.2^Type of preservatives ^18 Table 3.3^Preservatives' formulation ^19 Table 3.4^Evaluation of mold growth rating system ^24 Table 3.5^Summary of average mold growth of mixed hardwood strandboard after exposure to mold fungi for 6 weeks ^26 Table 3.6^Rank for the treatment ^32 Table 4.1^Type of preservatives ^36 Table 4.2^Summarization of solution uptake ^38 Table 4.3^Active ingredients loading formulation of each preservative "The first screen trial" ^40 Table 4.4^Active ingredient loading ratio for the second screen trial ^40 Table 4.5^Summary of average weight loss of yellow birch and southern pine after exposure to decay fungi for 6 weeks ^44 Table 4.6^Summary of average weight loss of LP 15849 ^45 Table 4.7^Summary of average weight loss of yellow birch and southern pine after exposure to decay fungi for 6 weeks ^46 Table 5.1^Preservative specifications ^52 Table 5.2^Effect of all preservatives concentration on the gelation time and viscosity of PF resin ^58 Table 5.2^Effect of all preservatives concentration on the gelation time and viscosity of PF resin —continued ^59 ^69 Table 6.1^Preservatives' retention levels Table 6.2^Average density profile of specimens from both outer and inner part of panels ^73 Table 63^Static bending properties of treated OSB ^75 Table 6.3^Static bending properties of treated OSB - continued ^76 Table 6.4^IB properties of treated strandboard ^81 ^82 Table 6.5^Mechanical properties of treated strandboard Table 7.1a^Average weight loss after 12 week of exposure to both brown-rot fungi ^91 Table 7.1b^Average weight loss after 12 week of exposure to both white-rot fungi ^92 vii  LIST OF FIGURES Figure 3.1^Cutting pattern of samples from panel "A"  ^16 Figure 3.2^Rolling Process (post-treatment) ^20 Figure 3.3^Testing molds ^22 Figure 3.4^Schematic of test apparatus for mold resistance ^23 Figure 3.5^The mold growth on specific strand on high retention level of preservative ^28 Figure 3.6^The mold growth on specific strand on LP 15896 (0.885 g/m 2 ) treated sample ^29 Figure 3.7^Mold growth based on mold coverage over 6 week exposure time ^31 Figure 4.1^Plates after inoculation ^37 Figure 4.2^Petri dish of wood block before and after 1 st screen trial ^42 Figure 5.1^Viscosity measurement ^54 Figure 5.2^Gelation time measurement ^55 Figure 53^Solid formation of LP 15853 ^57 Figure 5.4^Effect of fenpropimorph on the gelation time and viscosity compare to pure PF resin ^60 Figure 5.5^Comparison of gelation time "8.35 % Fenpropimorph + 10% KHDO vs. 8.35% Fenpropimorph" ^61 Figure 5.6^Comparison of viscosity "8.35 % Fenpropimorph + 10% KHDO vs. 8.35% Fenpropimorph" ^62 Figure 5.7^Comparison of gelation time "8.35% Fenpropimorph vs. 8.35% Fenpropimorph + 8% organic fungicide" ^63 Figure 5.8^Comparison of viscosity "8.35% Fenpropimorph vs. 8.35% Fenpropimorph + 8% organic fungicide" ^63 Figure 5.9^The effect of preservative V on the gelation time and viscosity of PF resin ^64 Figure 6.1^Cutting pattern diagram ^71 Figure 6.2^MOR/MOE testing ^72 Figure 6.3^Internal bonding testing ^72 Figure 6.4^Example of outer (a) and inner (b) part sample from panel ^74 Figure 6.5^Comparison of mechanical properties "8.35% Fenpropimorph + 8% organic fungicide vs. 8.35% Fenpropimorph" ^77 Figure 6.6^Comparison of mechanical properties of boric acid ^78 Figure 6.7^Comparison of mechanical properties "8% organic fungicide + 30% K-DHO" ^79 ... vill  Figure 7.1  Southern pine sapwood after 12 weeks of exposure to white and brown-rot fungi  ^90  Figure 7.2  Decay resistances of untreated test blocks  ^93  Figure 7.3  Average mass losses of preservative I due to decay fungi  ^94  Figure 7.4  Average mass losses of preservative IV and V vs. 0.83% ZnB^95  brown-rot Figure 7.5  Average mass losses of preservative IV and V vs. 0.83% ZnBwhite-rot  ^96  Figure 7.6  Estimation of biocide toxic threshold retention for preservative I^98  Figure 7.7  Estimation of biocide toxic threshold retention for preservative ^ II  98  Figure 7.8  Estimation of biocide toxic threshold retention for preservative ^ III 99  Figure 7.9  Estimation of biocide toxic threshold retention for preservative ^ IV 100  Figure 7.10  Estimation of biocide toxic threshold retention for preservative ^ V 100  Figure 7.11  Estimation of biocide toxic threshold retention for preservative ^ VI 101  ix  LIST OF ABBREVIATIONS  ACQ^Ammoniacal copper quaternary ACQPPZ^Ammoniacal copper quaternary piperazine ACA^Ammoniacal copper arsenate ACZA^Ammoniacal copper zinc arsenate ASTM^American society for testing and materials AWPA^American wood-preservers' association CA-B^Copper azole with boron CCA^Chromated copper arsenic CSA^Canadian standards association DDCA^Didecyldimethylammonium chloride IAQ^Indoor air quality IPBC^3-iodo-2-propynybutylcarbamate K-HDO^N-cyclohexyldiazeniumdioxy-potassium LVL^Laminated veneer lumber MSDS^Material Safety Data Sheet OSB^Oriented strandboard PF^Phenol formaldehyde pMDI^Polymeric diphenylmethane diisocyanate PPZ^Piperazine ZnB^Zinc borate BSF^Billion square feet cPs^Centipoise DF^Degree of freedom GPa^Giga Pascal IB^Internal bonding kPa^Kilo Pascal MC^Moisture content MPa^Mega Pascal MOE^Modulus of elastic MOR^Modulus of rupture lb^Pound g/m2^Gram per square meter kg/m 3^Kilogram per cubic meter mm^Millimeter ,um^Micrometer ° C^Degree Celsius  x  ACKNOWLEDGEMENTS  I am very thankful for endless help, erudite knowledge in wood preservation and, many opportunities afforded by Dr. John N.R. Ruddick, my major professor. I also wish to express my gratitude to committee members, Dr. Greg Smith and Dr. Stavros Avramidis for their valuable suggestions and technical support throughout my research. I greatly appreciate the technical support and valuable advice and discussion provided by Mr. Rainer Wisberger and Mr. Herr Hettler (Dr. Wolman GmbH, Germany), on my study and the financial support from Dr. Wolman GmbH. Without their support, this project could not have been completed. I would also like to thank to all those at the Department of Wood Science who helped directly of indirectly with my Master's program. Finally, I am also very thankful for the patience and encouragement of my wife, SooKyong, without which I would not have accomplished the research.  xi  CHAPTER 1 Background 1.1 Introduction In North America, homes frequently have aspen/poplar-based Oriented Strandboard (OSB) panels as sheathing and may also include OSB webbing in I-joints to support flooring. OSB is made from strands of mixed hardwood such as aspen (Populus tremuloides Michx.), poplar (Populus balsamifera), and softwoods such as spruce (Picea sp) and southern pine (Pinus spp.). Orienting the strand provides increased strength properties along the long panel dimension. OSB is increasingly being used as a replacement for plywood in structural applications, such as wall sheathing, roof sheathing, sub flooring, underlay, and structural insulated panels. The competitiveness of OSB lies in its use of lower quality, less expensive wood sources, the fact that recovery of fiber in the stranding process is high, and its properties are similar to plywood (Howard 2001). In 2000, OSB production in North America exceeded 1.93 billion m 2 , overtaking that of plywood (Najera and Spelter, 2001). Wood strands are glued with an exterior grade waterproof resin such as phenol formaldehyde (PF) resin or polymeric diphenylmethane diisocyanate (pMDI) resin. The mechanical properties of the boards are enhanced by layering and alignment of wood strands. As structural engineered wood composites are being used more frequently to replace solid sawn timber, they are sometimes placed in challenging environments. These more demanding environments often may lead to increased risk of exposure to moisture. However, OSB panels, like conventional wood products, are susceptible to mold growth and decay when conditions are suitable for fungal growth, which has resulted in significant economic consequences. Over the past decade, concerns about indoor air quality (IAQ) due to mold growth and decay in condominium wall components have increased dramatically in North America. The problems of mold and decay fungi have become more common due to the changing architectural building -1-  designs with low roof overhangs resulting in a more severe exposure of the wall to rain. In additional more complex designs have results in greater potential for failure of the wall, particulars where decks or other breaks in the wall integrity occur. Further the use of elastomeric stucco results in any moisture which penetrates into the wall cavity, being unable to drain or evaporate. The wall components then remain wet for prolonged periods causing decay and mold growth. The presence of even a relatively low moisture content of 20% promotes growth of mold, which has become a major concern in buildings in North America due to health problems related to selected mold fungi. Concern over toxic mold (Stachybotrys chartarum or Stachybotrys atra), also known as black mold, has become a major health issue for home builders and homeowners in North America (Vlosky 2004). However, the black mold is uncommon in most homes. The majority of the molds found in homes are Cladosporium sp, Penicillium sp, and Alternaria sp, which nevertheless are now known to cause chronic sinus infection, respiratory infections, and asthma. Increasing problems of mold in wood building products costs the insurance industry in North America millions of dollars annually. Support for the need for more durable sheathing or panel products can be found in the litigation over residential flooring in Alberta and the leaking condominiums in British Columbia in the late 1990s. Millions of dollars in lawsuits and "clean up" are ongoing to rectify the problem are focusing attention on toxic, mold-related illness from the "leaky" OSB sheathed buildings (Poitras 2005). Wood decay basidiomycetes fungi, are probably the most destructive biological pathogens of wood structures because they can cause rapid structure failure. In the U.S. alone, the annual cost due to decay of wood components in residential structures amounts to about $ 5 million, and the labor involving in repairing this damage further increases this cost to $ 5 billion per year (Green III and Schultz 2003). Wood decay basidiomycetes fungi encountered by homeowners fall into two basic categories: brown-rot fungi and white-rot fungi. -2-  The most effective control of decay and mold growth is through the application of suitable biocides. Since the mid 1970s, the main wood preservative used in residential construction in North America was waterborne chromated copper arsenate (CCA). Since 2003 this has been replaced by copper-organic mixtures, such as alkaline copper quat (ACQ) and copper azole mixtures, with or without boron (CBA-A and CA-B). Wood treatment with copper-organic mixtures preservative demonstrates very low risks to both human in contact with treated wood and also the environment. Since copper has potential to impact aquatic systems negatively, and disposal of any metal-treated wood product may be expensive and difficult in the future (Green III and Schultz 2003) efforts are being made to develop purely organic biocide. Several countries in Europe are already moving towards totally organic wood preservative systems. Zinc borate has been used as an additive to resin during manufacture of OSB, However, limited effectiveness, difficulty of coating strands effectively, and potential for leaching together with a decrease in the mechanical and physical properties of strandboard bonded with PF resin (Lee 2003), stimulate ongoing research for superior biocides for use in wood composites. Consequently, new organic wood preservatives for residential use based solely on organic fungicides or a combination of organic fungicides are being developed. These preservatives based on fungicides which while well know in agriculture, are relatively new for protection of wood. Knowledge about their effectiveness is limited and their long time protection, in many cases, is unknown (Edlund et al. 1999). Most of these preservatives have been used to protect wood intended for above ground construction, or provide relatively short term protection to unseasoned wood. This study was divided into two phases. The first phase examined the effect of different fungicides or combinations of fungicides on the mold resistance properties of strandboard. The second phase examined the effect of different fungicides or combinations of fungicides on the decay resistance properties of strandboard. To complete the second phase, several experiments -3-  were done to examine the effectiveness of individual fungicides or combination of fungicides in agar-block test to estimate the preservative toxic threshold retention. In addition, the changes in resin gelation and viscosity when biocides were incorporated into the resin were measured. After these studies were completed the mechanical and decay resistance properties of preservative treated strandboard were assessed. Fungicides or combination of fungicides included in this study were based on fenpropimorph, propiconazole, 3-iodo-2-propynylbutylcarbamate (IPBC), and boric acid for the mold resistance study. For decay resistance experiment, Ncy clohexyldiazeniumdioxy -potassium (K-HDO), fenpropimorph, and organic fungicide (confidential information) were used.  1.2 Objectives  This research is focused on finding preservative system with low environmental impact and low human toxicity which can be added to resin during OSB manufacture. Specific objectives were: 1. to investigate the effect of different fungicides on the resistance of strandboard against mold fungi. 2. to find the minimum amount of biocide which is effective in preventing decay under optimum laboratory conditions. 3. to examine the compatibility of different types of fungicide or combinations of fungicide, with phenol formaldehyde (PF) by measuring changes in gelation time and viscosity of the PF resin in order to identify desirable combinations of the two components. 4. to investigate the effect of fungicide type and application levels on the mechanical properties (MOE, MOR, and IB) using individual fungicides or combinations of fungicide treated strandboard. 5. to evaluate the efficacy of different fungicides against major basidiomycetes fungi -4-  using the AWPA E-10 standard evaluation method.  1.3 Outline of Thesis  This thesis is divided into 9 chapters. Chapters 1 and 2 introduce the research topic and provide background to research problems addressed in the thesis. Chapter 3 presents mold resistance properties of treated strandboard. Chapters 4 and 5 present the result of fundamental evaluation and the impact on the fungicides on the viscosity and gelation time of the PF resin. Chapter 6 discusses the effects of the various biocides at different retention on the mechanical properties of treated strandboard. Chapter 7 presents the decay resistance of the treated strandboard. The effects of preservative retention on decay resistance of the treated strandboard against white and brown-rot fungi examined and discussed. Finally, Chapter 8 and 9 present the conclusion and recommendations of the research.  Chapter 2 Literature review: Protecting wood composite products 2.1 Oriented strandboard Oriented strandboard, an engineered structural panel, is widely used for house construction as exterior sheathing, roof sheathing, flooring, and also as a component of I-joint. In 2004, OSB production in North America exceeded 25,374 BSF (3/8"), while plywood production exceeded 17,304 BSF (3/8"). OSB production in North America will reached 65% of the market share by 2007 and it is the most common structural sheathing material for residential buildings where it accounts for 72% of roofs, 65% of floors and 56% of walls. One of reason why more wood composites are being used to replace solid sawn lumber is the decreasing availability of large diameter raw material suitable for producing solid wood product. OSB was first developed in 1954 (Lowood 1997) as an engineered structural panel. OSB is composed of compressed strand arranged in layers oriented a right angles to one another. The strands are prepared from small dimension timber, for example trees harvested during plantation thinning, or branches, as well cut from fast-growing species (Howard 2001). Exterior or surface layers are composed of strands aligned in the long panel direction, and inner layers consist of cross or randomly aligned strands. These mats are the subjected to intense heat and pressure with exterior grade adhesive. The physical and mechanical properties depend on strand orientation (Nishimura et al. 2004). The strength of OSB comes mainly from the uninterrupted wood fiber, overlapping of the long strands or wafers, and degree of orientation of strands in the surface layers and the use of waterproof resin binders which provides internal strength, rigidity, and moisture resistance (Najera and Spelter 2001).  -6-  2.2 Problems of OSB as structural panel OSB is being increasingly used as a critical structural component in environments where it may be exposed to physical or biological agents of deterioration (Morris 1995). It may be thought that OSB would be resistant to fungal degradation because the PF resin customarily has a high pH and the presence of non-condensed phenol would deter fungal colonization (Schmidt et al. 1978). However, in practice, OSB, like other wood based composites, is susceptible to colonization by mold, decay, and staining fungi when conditions are optimal for fungal growth. The reason OSB is susceptible to attack by fungi and insects is that non-condensed phenol are low in concentration and can be leached easily. Changing architectural building designs with shallow roof overhangs, combined with improper construction with a tighter structure, which does not allow moisture to escape, have led to increased moisture levels, in wall cavities in residential buildings, which can promote fungal problems of stain, mold and decay fungi. Common sources of moisture are bathrooms with poor ventilation, a leaking roof, plumbing, improperly vented clothed dryer, and flooding (Fogel and Lloyd 2002). Chronic moisture in a structure can lead to a cascading biological succession from mold to decay fungi to insect infestation. Moisture is the key ingredient for all three types of biological damage to structure. The presence of moisture on wood surfaces promotes the growth of mold. Although common molds found inside walls and attics have not been scientifically linked to health problems, but their spores are thought to cause illnesses in people allergic to pollen, spores, etc. The biggest concern has been with the black mold, Stachybotrys chartarum or Stachybotrys atra. This mold while found on plasterboard, rarely grows on wood products. Many of the problems of wood-based composites were highlighted during the 1990s when numerous civil lawsuits were filed concerning building failure leading to decay. Subsequently, mold problems have been well documented and received publicity during the late 1990s and into 2000s (Kirkpatrick 2005). Residential flooring in Alberta and the leaking condominiums in -7-  British Columbia in the late 1990s provide the evidence (Poitras 2005). Decay fungi are probable the most destructive biological pathogens on wood structures in North America because it can cause structural failure, sometimes very rapidly. The most effective solution against fungal degradation is the use of preservative treated wood-based composite products in residential construction. A major concern with wood-based composite products such as OSB is the complexities and opportunities not found in the centuries old practice of solid wood preserving. Unlike solid wood, biological protection may not be incorporated into wood-based composite products by pressure/vacuum treatment processes with a waterborne preservative, by diffusion of liquid based systems over time, or by surface coating due to the significant swelling problems, as well as the cost-due to the need to re-dry the products. Another means of incorporating preservatives into wood composite panels is by mixing or blending the preservatives in the resins prior to spraying the resin onto furnish. However, one must then concern themselves with possible adverse effects on product properties, which is the focus of this investigation.  2.3 Applying OSB protection During the past decade, academic and industry have studies to improve durability of woodbased composite product by wood preservative treatment. Table 2.1 shows the work done by Gardner and co-workers (2003) using 18 different types of preservative. Wood-based composite products offer complexities and opportunities not found in the centuries old practice of solid wood preserving (Kirkpatrick 2005), because wood-based composite products, especially OSB cannot be pressure-treated with waterborne preservatives once it is made into panel due to its large swelling characteristics.  -8-  Table 2.1 Wood Composites and Preservative Treatments (Gardner, et al. 2003, and Kirkpatrick 2005)  Composite Type^Treatment Chemical  Glu-lam Timbers  Plywood  ^ACQ, CCA, CA-B, copper naphthenate, Copper-8 creosote, penta, IPBC-CPF ACA, ACZA, ACQ, CCA, CA-B, PPZ, TEB, permethrin, deltamethrin, bifenthrin, DOT imidacloprid, arsenic trioxide, glycol borates,  ^  CCA, PPZ, TEB, permethrin, deltamethrin, bifenthrin, Laminated Veneer Lumber imidacloprid, arsenic trioxide, glycol borates, penta, copper(LVL) 8 Parallel Strand Lumber  CCA, creosote, penta, copper naphthenate, copper-8, copper azole, ACQPPZ, TEB, permethrin, deltamethrin, bifenthrin, imidacloprid  Oriented Strandboard (OSB)  Zinc borate, copper complex, copper, cypermethrin or permethrin, IPBC plus chlorpyrifos or permethrin  Laminated Strand Lumber^Zinc borate, IPBC plus chlorpyrifos or permethrin ^ Particleboard Fire retardant, permethrin Fiberboard ^Fire retardant, zinc borate, boric acid (Mediumdensity fiberboard) Hardboard^Fire retardant I-Joists^ IPBC-CPF in light organic solvent Wood plastic composites^Zinc borate  There are three ways (pre-treatment, in-line, and post-treatment) to apply preservative treatments to these materials. The method of incorporation may depend upon the type of woodbased composite products. In-line treatment is often done for strand-based composite (Wu 2004). 9  Chapter 3 The evaluation of fungicides or combinations of fungicides for protecting OSB against mold growth 3.1 Introduction  Wood-based composites especially Oriented Strand Board (OSB) is being increasingly utilized in both interior and the principal structural elements in buildings. However, growth in some structural applications is still limited because of their sensitivity to excessive levels of moisture. A warm, wet, or humid environment provides ideal conditions for the development of mold and mildew on a variety of surfaces, including OSB structural panels. This problem has become more common due to the construction of more air tight structures, which do not allow moisture to escape. Surface treatment or incorporating a preservative into engineered products would add an additional layer of protection for in-service wood products. Clearly, treating construction materials with an effective biocide would lessen the impact of current indoor air quality issues. This strategy is already being employed in the manufacture of some building materials, such as gypsum and OSB (Fogel and Lloyd, 2002). The most commonly used biocide formulations for mold (sapstain) control are based on the quaternary ammonium compound didecyl dimethyl ammonium chloride (DDAC) with or without co-biocide (Dubois et al. 2000). NP-2 is the most commonly used product that is a concentrated anti-sapstain and broad spectrum wood preservative treatment chemical containing a combination of DDAC and 3-iodo-2-propynyl butylcarbamate (IPBC) that work synergistically (KOP-COAT  TM  ,  INC., 2001). Several studies  indicated that, combinations of biocides with different modes of action for controlling fungi may provide broader spectrum protection because of the possible complementation or synergism among biocides (Presnell and Nicholas, 1990; Laks et al., 1991). Other preservatives for OSB - 13 -  anti-mold treatments such as propiconazole, fenpropimorph, and boric acid also indicate excellent activity against mold. Studies have been done on the relative susceptibility of azole-based treated wood products to mold fungi. Three of eight antifungal azole compounds tested were efficacious against A. niger, P chrysogenum, and T viride on dip-treated yellow pine (Clausen and Yang 2004). In research described here, the laboratory evaluation of mixture of several fungicides or combinations of fungicide and metal-containing preservative based on propiconazole, fenpropimorph, boric acid, and IPBC, which was obtained by Dr Wolman GmbH, were used as OSB anti-mold treatment, and NP-2, a combination of DDCA and IPBC , which is the most widely used biocide for mold control on freshly cut lumber, was used as a reference treatment for assessing the resistance of surfaces of wood products to mold growth.  3.2 Materials and Methods 3.2.1 Wood  Four commercial OSB panels (1219 mm x 1219 mm x 11 mm) mixed hardwoods and softwood (65% aspen, 10% pine, 20% of soft maple and 5% of hard maple) containing 1% wax were used for this experiment. These OSB boards were obtained from Weyerhaeuser. For comparison, untreated ponderosa pine "Pinus ponderosa" sapwood control samples were cut from a timber (100 mm x 76 mm x 11 mm), which was obtained from Forintek. In preparing samples for preservative treatment, both surfaces of all OSB board samples were sanded (approximately 0.74 mm + 0.05) to improve the surface smoothness. Each OSB board was then sawn into 7 strips (approximately 75 mm wide x 1219 mm long) and each strip was individually labeled. Each strip was then further sawn to produce to the test samples with the required dimensions (approximately 75 mm x 100 mm). Each strip produce 11 samples (Figure 3.1). 240 samples were divided into 12 subgroups of 20 samples for treatment with one of the test fungicides. After dividing into 12 subgroups, all samples were individually labeled. For each of the 12 subgroups, the 20 samples were divided again into sets of test samples: 6 test samples for evaluation at UBC, a matching 6 test samples for use by Dr. Wolman GmbH at Sinzheim, Germany, and 6 test samples retained for assay for the fungicides. The remaining two samples we retained as spare in case of wide variation in uptake during treatment. The detailed sample labeling is summarized in Table 3.1.  75mm  E  MC sample  MC MC MC MC MC MC sample sample sample sample sample sample  A-a-1  A-b-1  A-c- 1  A-d- 1  A-e- 1  A-1-1  A-g- 1  A-a-2  A-b-2  A-c-2  A-d-2  A-e-2  A-1-2  A-g-2  A-a-3  A-b-3  A-c-3  A-d-3  A-e-3  A-f-3  A-g-3  A-a-4  A-b-4  A-c-4  A-d-4  A-e-4  A-1-4  A-g-4  A-a-5  A-b-5  A-c-5  A-d-5  A-e-5  A4-5  A-g-5  VT,  E  E  cn  A-a-6  A-b-6  A-c-6  A-d-6  A-e-6  A4-6  A-g-6  A-a-7  A-4-7  A-c-7  A-d-7  A-e-7  A4-7  A-g-7  A-a-8  A-b-8  A-c-8  A-d-8  A-e-8  A-1-8  A-g-8  A-a-9  A-b-9  A-c-9  A-d-9  A-e-9  A-1-9  A-9-9  A-a-10 A-b-10 A-c-10 A-d -10 A-e-10 A-F-10 A^0 A-a-11  A-b-11 A-c-11  A-d-11  A-e-11  A4-11  A-g-11  1219 mm  Figure 3.1 Cutting pattern of samples from panel "A"  The upper case letter refers to the notation of the original source board. The lower case letter refers to different strips produced from the original source board, and the number refers to the different sample cut from each strip.  ^  Table 3.1 The detailed sample identification for the chemical treatment  Chemical^Retention (g/m 2 )^Sample No.  ^0.450^A-a-1, B-b-10, B-f-4, C-c-1, D-b-10, D-f-11 ^ LP 15895 0.225^A-a-7, A-f-5, C-a-5, C-b-11, C-d-2, D-d-6 0.113^A-a-2, A-d-6, B-c-11, C-c-8, D-a-9, D-b-8 1.710^A-c-1,A-f-3, B-c-3, C-a-10, C-d-6, C-f-9 LP 15896  ^  0.855^A-c-6, A-d-11, B-d-9, C-a-6, C-e-8, D-c-1  0.428^A-c-8, B-e-11, C-c-9, D-b-7, D-c-11, D-e-11 0.500^A-a-6, A-f-1, B-e-1, C-d-8, D-b-4, D-d-1 LP 15850  ^  0.250^A-c-11, B-a-4, B-c-1, C-c-3, D-a-5, D-f-5  0.125^A-c-2, A-f-8, B-a-11, B-f-1, C-f-8, D-c-4, 1.505^A-c-7, A-f-7, B-f-3, C-b-1, C-f-7, D-e-7, NP-2  ^  0.752^A-f-4, A-g-3, B-c-9, D-d-11, D-f-4, D-g-9,  0.376^A-e-4, A-g-7, B-g-4, C-c-11, D-a-7, D-d-4,  The moisture content (MC sample) was measured using samples cut from each panel. The moisture content sample cut from each strip from each board was weighed (W 1 ), oven dried for 24 hours at 105 C, and re-weighed (W2). The moisture content was determined from W1 - W2  MC (%) - ^ X 100 W2  Where MC is the moisture content (%), W 1 is initial weight of the test sample (g) and W2 is weight of the oven dried test sample (g).  - 17 -  3.2.2 Preservatives Four preservatives were used: LP 15895, LP 15896, and LP 15850 provided by Dr. Wolman GmbH and a commercial formulation, NP-2, from Kop-Coat. The general description of each preservative taken from their Material Safety Data Sheet (MSDS) is given in Table 3.2. Table 3.2 Type of preservatives  Trade name  pH  Chemical name Propiconazole  4.5  IPBC**  4.5  Fenpropimorph  1.5  Propiconazole  2.7  Fenpropimorph  5.4  Boric acid  9.0  DDAC*  70.48  IPBC**  4.76  LP 15895  6.15-6.5  0.9  LP 15850  5.3  0.92  LP 15896  NP-2  7  7.9  Active ingredient  Density (g/cm 3)  0.95  <1  (%)  * Didecyl Dimethyl Ammonium Chloride **3-lodo-2-Propynyl Butyl Carbamate  3.2.3 Formulation preparation The four preservatives were diluted with distilled water before applying on the surface of board. To achieve the target loading for each formulation provided by Dr. Wolman GmbH, the dilution ratio for each treatment were varied as shown in Table 3.3. The dilutions in Table 3.3 were based on a weight of water versus weight of formulated chemical solution, as provided by - 18 -  ^  Dr. Wolman GmbH. Table 3.3 Preservatives' Formulation  Target Trade name^Undiluted biocide^Distilled water^Dilution^loading (g/m2)  48.940g^451.060g^9.2:1^0.450 LP 15895  25.730g^474.358g^18.4:1^0.225 13.203g^486.834g^36.9:1^0.113 48.940g^451.060g^9.2:1^1.710  LP 15896  25.730g^474.358g^18.4:1^0.855 13.203g^486.834g^36.9:1^0.428 39.930g^460.400g^11.5:1^0.500  LP 15850  20.795g^479.242g^23.0:1^0.250 10.618g^484.616g^46.1:1^0.125 10.618g^489.394g^46.1:1^1.505  NP-2  5.366g^494.649g^94.2:1^0.752 2.701g^497.351g^184.4:1^0.376  3.2.4 Sample preparation  To obtain target loading formulation for LP 15895, LP 15896, and LP 15850 as recommended by Dr. Wolman, solution of each moldicide were applied to the surface of extra samples to achieve the target solution uptake before applying on the test samples. Using the information from the trial, treatments were then done on the actual samples. The solution was applied each sample (approximately 75 mm x 100 mm) individually using a paint roller. Preservatives were - 19 -  applied by double brushing. Figure 3.2 shows a sample being treated with fungicide. Prior to treatment, both the sample and the roller were weighed. After applying treatment to one side of each sample, the sample was weighed to determine the mass uptake of the preservative solution. Once the front side is dried, the other side of the sample was then treated and then the sample weighed again to determine how much solution was retained. After applying treatment on both sides of sample, the final weight gave the total surface retention. The roller and tray were also weighed to determine how much solution remained. The solution uptake was based on the difference in the OSB sample weight before and after treatment. Treated samples were stored in conditioning room for three weeks at 20 ° C and 65 percent relative humidity (RH) before using in the mold test.  Figure 3.2 Rolling Process (post-treatment)  - 20 -  3.2.5 Preparation of mold inoculum  Alternaria alternata 691 B, Aspergillus niger 207 F, Aureobasidium pullulans 132 F, and Penicillium citrinum 595 C were maintained on 2 percent malt agar (Forintek, Vancouver) (Figure 3.3). Spore inocula were prepared by carefully scraping the surface of individual 2-weekold cultures of each fungus with a blunt scalpel, and the distilled water were added into petri dish. The transferred spore suspensions were gently agitated and poured into a blending container to mix at high speed for 15 seconds. The liquid spore suspension were combined and rinsed with distilled water and filtered through sterile glass wool to remove any large particles and media from the suspension. The filtered liquid spore suspension were transferred into a 1000 ml beaker and additional sterile deionized water was added to give a final volume of 1000 ml. Prior to introducing test samples, the mold inoculum was distributed evenly over the surface of potting soil using a 50 ml pipette. The chamber was allowed to incubate for two weeks prior to the introduction of the test samples.  11  Penicillium citrinum 595C  ^  Aureobasidium pullulans 132F  F21 Aspergillus niger 207F  ^  0  Altemaria alternate 691 B  Figure 3.3 Testing molds  3.2.6 Addition of samples to the mold chamber  Six samples for each treatment and controls for a total of 56 samples were placed in specially designed racks. The bottom of the sample was approximately 75 mm above the surface of the inoculated potting soil. The soil was contained in an acrylic unit (60 x 40 x 10 cm) which has a stainless steel mesh resting on the bottom that was covered with a polyethylene mesh screen. The samples were place with the long dimension vertical and parallel to each other so that the faces were perpendicular to the fan air flow. This allowed free circulation of air in the test chamber. The sample locations from each treatment were randomized. The individual sample locations - 22 -  were also recorded in case mold growth obscured the sample labeling.  a polyethylene  AM mesh screen  * Water and heating device were located under the potting soil.  Figure 3.4 Schematic of test apparatus for mold resistance  All sample surfaces were evenly inoculated with a trigger sprayer using the same mold  inoculum as described in Section 3.2.5. All samples were visually rated weekly for the percentage of surface mold coverage. 3.2.7 Mold growth rate system  The percentage of surface of sample discolored was evaluated based on two categories (mold coverage and intense growth) on a visual basis each week for 6 week. The result of mold growth - 23 -  was reported as means with standard deviations (Table 3.4). A rating of mold coverage 4 or 5 refers to low density growth over most of the sample area. Table 3.4 Evaluation of mold growth rating system  Description Rate  Mold coverage  0  None  1  Intense( colored) growth  Rate  0  0  Trace of growth (< 10 %)  More than 5%  1  2  Light growth (10 % — 30 %)  More than 10%  2  3  Moderate growth (30 % — 70 %)  More than 30%  3  4  Thin growth (> 70 %)  More than 70%  4  5  Thin growth (100 % or < 100 %)  Greater than 70%  5  Source: AWPA draft  3.2.8 Statistical analysis  A statistical analysis based on a one-way analysis of variance (ANOVA) was performed to identify the effectiveness of each preservative at the three retention levels. A Turkey-Kramer's test was conducted after the analysis of variance to determine the differences among the means. For the statistical analysis, a level of confidence of 95% (p=0.05) was used.  3.3 Results and Discussion 3.3.1 Mold Resistance properties The test data of the mold resistance of treated OSB samples are summarized in Table 3.5. The data presented is the mean value of the 6 samples prepared from each treatment, the untreated solid ponderosa pine sapwood and an untreated mixed hardwood OSB control. The values in parenthesis represent the standard deviation. As shown in Table 3.5, untreated OSB and solid pine sapwood samples exposed to the mixture of the mold fungi (Alternaria alternate 691 B, Aspergillus niger 207 F, Aureobasidium pullulans 132 F, and Penicillium citrinum 595 C) were being susceptible to mold growth (rating of 4.25 and 4.08 respectively). The high mold growth rate on untreated OSB confirmed that neither the presence of free phenolic and formaldehyde from the adhesive nor the wax water repellant prevented mold growth. The adhesive residue is susceptible to leaching and volatilization, so it can not provide lasting protection (Bravery and Lea 1987). The solid pine sapwood samples also were extensively covered with mold growth. These results are expected since at the high moisture content, mold can be established on wood in 24 — 48 hours if temperature and humidity conditions are optimal (Clausen et al. 2004). In comparing the different preservatives (Table 3.5), all except LP15850 significantly reduces the mold growth (ratings of 1.42 to 2.50, respectively). Greater protection of the OSB was achieved as the preservative retention level increased. However, the physical structure of the OSB surface (void distribution, and the size of flakes) together with the variation in the different wood species of the flakes also influenced the mold growth. From the results of experiment, the wood species was a major factor that influenced the mold growth. As shown in Figure 3.5, some strands in the OSB samples treated to the highest retention had higher mold growth than strands treated to a lower retention. Analysis of the problematic strands showed the cause of higher mold growth rate was the presence of either hard maple (Acer saccharum Marsh.) or soft maple (Acer - 25 -  rubrum L.). The hard maple and soft maple flakes, on the surface of OSB were more susceptible to mold growth than lodgepole pine flakes and aspen flakes. This phenomenon appeared on the maple strands after the second week and throughout the test (Figure 3.6). Table 3.5 Summary of average mold growth of mixed hardwood OSB after exposure to mold fungi for 6 weeks  Treatment  Retention (g/m 2)  Mold growth (%)  Untreated, ponderosa pine sapwood  0  95 (4.687) **  a*  Untreated, sanded OSB  0  98 (2.575)  a  Untreated, waxed OSB  0  98 (2.462)  a  0.125  68 (6.557)  b  0.250  48 (10.326)  c  0.500  28 (12.309)  d  0.428  20 (12.147)  ef  0.855  13 (7.217)  f  1.710  5 (2.570)  g  0.113  18 (13.334)  ef  0.225  8 (6.360)  gf  0.450  4 (3.040)  g  0.125  24 (14.041)  e  0.250  13 (4.250)  gf  0.500  6 (4.112)  g  LP 15850  LP 15896  LP 15895  NP-2  *Data with the same lowercase letter within a group show no significant difference at the 5% significance level within each content. **Values in parenthesis represent one standard deviation.  - 26 -  The reason the mold growth is more susceptible in the maple flakes is presumably related to the nutrients content such as low molecular weight carbohydrates, glucose, xylose, mannose, galactose, and arabinose, available on the surface on strand. In addition hardwood hemicelluloses are rich in pentosan (xylan), which is generally the least thermally stable hemicellulose with a decomposition temperature around 200 ° C (Beall 1970). It has been reported that there is a significant relationship between mold growth and carbohydrate content (Terziev and Boultelje 1998), and that the presence of carbohydrates with a low molecular weight showed greatly enhanced the susceptibility of wood to mold attack (Theander 1993). In addition, the anatomy of hardwood, especially maple, makes it more susceptible to mold attack compared to other species, since it has larger and more frequent ray cells. Therefore, it is easier for fungal hyphae to penetrate into the wood structure where the carbohydrates are present. The inclusion of both heartwood and sapwood also influenced the mold growth over all preservative retentions. Sapwood flakes would be expected to easily absorb solution, whereas heartwood flakes would be more resistant to solution uptake. Overall, the void distribution in the OSB sample did not significantly influence the mold growth. However, some samples treated to a higher preservative retention produced a higher mold growth rate than corresponding samples treated to lower retention of preservative. This phenomenon is most likely due to the penetration of significant preservatives solution into the void spaces between flakes rather than the absorption on the surface. The results of the mold growth and rating of individual OSB samples tested on UBC are summarized in Appendix Al to A4.  NP2-1.505 g/m 2^LP15850-0.500 g/m 2  LP15895-0.450 g/m 2^LP15896-1.710 g/m 2 Figure 3.5 The mold growth on specific strand on high retention of preservative  - 28 -  before  ^  4 weeks  ^  2 weeks  6 weeks  Figure 3.6 The mold growth on specific strand on LP 15896 (0.885 g/m 2 ) treated sample  - 29 -  3.3.2 Evaluation of mold growth in every week The detailed weekly evaluations of mold growth are plotted in Figure 3.7. All of the OSB samples showed an increase in mold coverage over the 6 week exposure period. In the initial stages of control, solid ponderosa pine sapwood had approximate 22% less mold growth than untreated OSB. As was mentioned in Section 3.3.1, hardwood is more susceptible to fungal attack than softwood presumably due to the nutrients content. The OSB surface with its voids also could influence the mold growth on untreated OSB. However, at the end of test, the mold growth on the untreated OSB and ponderosa pine sapwood were almost identical. The mold growth on control samples increased slowly during the first week of exposure, and then tended to increase rapidly through out the test. This can be explained by the need for the sample surface to increase in moisture content to become optimal for mold growth. According to the one-way ANOVA (Appendix B 1), the differences in untreated wood samples had no significant effect on mold growth (P<.0001) at the 5% significance level (Table 3.5). For the treated OSB samples, several of the treated OSB samples had some mold growth on the surface after 2-week exposure to mold fungi (e.g. Appendix A2). This indicated that some preservatives can not completely protect OSB samples against mold attack. After 2-week exposure, the susceptibility of individual OSB sample exposed to mold attack varied with the preservatives and retention levels. Greater protection of the OSB was achieved with an increase in chemical retention level and also difference for the different preservatives. Based on the study, preservatives, which contained propiconazole and/or fenpropimorph with boric acid, and a combination of DDAC and IPBC, prevented the mold growth effectively. For comparison, the commercial anti-mold treatment, NP-2 at a retention of 0.752 g/m 2 , which is recommended retention level given by the manufacturer was used as toxic threshold for mold resistance study. The commercial anti-mold treatment, NP-2 at a retention of 1.505 g/m 2 , and moldicides from Dr. Wolman GmbH, LP 15895 (retention 0.225 g/m 2 and 0.450 g/m 2 ) and LP 15896 (retention - 30 -  1.710 g/m 2 ), provided better protection than NP-2 at a retention of 0.752 g/m 2 . These moldicides effectively prevented mold growth of 5 to 8% respectively at the end of 6 week exposure. However, a combination of IPBC and fenpropimorph was not effective in preventing the mold growth on OSB. According to the one way ANOVA (e.g. Appendix Cl), the main factors effect performance were biocide type and retention, and differences were significant at the 5% significance level.  100 98  •  96 9.1  F  a. 0  10 8 6  4  2 0  1st  ^  2nd^31d^4th^5th E xpns me time to ino^week)  ^  6th  NP2 - 1.505g/m 1^-N-NP2 - 0.752g/ne ^-A- I. P151195 - 0.450g/m -41.-  1. P I 5895 - 0.2250W-0-1. P1.5896 - 1.710g/m 2  -410--  Pine  -a-sanded OSB^-waxed OSB  Figure 3.7 Mold growth based on mold coverage over 6 week exposure time  - 31 -  Table 3.6 Rank for the treatment  Retention (g/m 2  Rank**  )  LP15895  0.450  1  LP15896  1.710  1  NP2  1.505  1  LP15895  0.225  2  NP2  0.752  3  LP15896  0.855  3  LP15895  0.113  4  LP15896  0.428  4  NP2  0.376  4  LP15850  0.500  4  LP15850  0.250  5  LP15850  0.125  6  Control-pine  0  7  Control-sanded OSB  0  7  Control-waxed OSB  0  7  Data with the same rank show no significant difference at the 5% significance level within each content ** Ranking based on ANOVA analysis of 6 week data shown in Figure 3.7 and detailed in Appendix B  3.4 Conclusions Based upon all of the examination in the study, the following conclusions may be made.  1)  The mold resistance of the OSB sample was directly related to the different preservatives and the concentration. The results suggested that the two highest concentrations of LP 15895, the highest concentration of LP 15895, and the two highest concentrations of NP2 can provide effective protection to OSB under severe conditions.  2)  At the highest concentration of LP15895 (0.225 g/m 2 and 0.450 g/m 2 ) and LP 15896 (1.710 g/m 2 ) from Dr. Wolman GmbH provided better protection than the current antimold product NP-2 when applied at its recommended commercial application rate of 0.752 g/m 2 .  3)  At the highest concentration of LP15895 (0.450 g/m 2 ) and LP 15896 (1.710 g/m 2 ) from Dr. Wolman GmbH gave numerically, lower mold rates than the highest concentration of NP-2 (1.505 g/m 2 ), which is a leading commercial anti-mold product. However, they were not statistically different when compared to 1.505g/m 2 of NP-2.  4)  Even with high concentrations of chemical, maple flakes on OSB were easily covered with mold in early stage of test. Therefore, the flakes used in this study should be further investigated.  5) It was difficult to macroscopically rate OSB samples because of color variations in the product. Better methods need to be devised for evaluating OSB products for mold growth.  Chapter 4  Estimation of fungicides or combinations of fungicides toxic threshold retention from laboratory decay test  4.1 Introduction Pure culture laboratory decay experiments are limited of usefulness for providing information on preservative retention required to protect wood under actual service condition. However, they are important when comparing the relative effectiveness of biocides, and allow an efficient approach to examining the potential of combinations of biocides to protect wood from decay fungi. The results of the studies provide a meaningful starting point for further evaluation (Przewloka 2004). In the current study, a series of fungicides was examined both individually, as well as in selected combinations. To optimize the screening evaluation an agar-block method, using miniaturized wood-blocks, was used. This method involves placing small wood blocks onto a petri plate containing a decay fungus growing on agar. The method provides mass loss data after 6 weeks. Once the toxic threshold values had been obtained with all fungi in the initial experiments, the most effective fungicides were formulated using the lowest toxic threshold values of each fungicide. For any fungicide where toxic threshold values could not be determined, another screening trial was done with either lower or higher retentions, depending on whether decay had been controlled or not prevented at all retention levels. The objective of this study is to find the minimum amount of preservative which is effective in preventing decay of selected wood species, by standard decay fungi under optimum laboratory conditions.  - 34 -  4.2 Materials and Methods  In order to find the toxic threshold, all fungicides had to be evaluated through two screening trials. A detailed description of the test methodology has been reported by Bravery (1978). 4.2.1 Wood  Wood blocks, measuring approximately 30 x 10 x 5 mm (end grain 10 x 5 mm) cut from yellow birch (Betula allegheniensis) and southern pine (Pinus spp.), were used for the screening studies. Yellow birch was selected to test against the white-rot fungus, Trametes versicolor (strain 105E) and southern pine was selected to test against the brown-rot fungus, Coniophora puteana (strain 9G).  In preparing samples for fungicide treatment, samples with defects, uneven grain, reaction wood, resin or which have rapid or slow growth rings are rejected since they could affect the uptake of chemical treatment and the final weight loss on samples. After careful screening, sufficient blocks to provide at least 6 blocks for each experimental variable were selected and labeled. All the blocks were oven dried at 105 ° C for 24 hours and the oven dry weights recorded. 4.2.2 Preservatives  Four preservatives formulation, LP 15842, LP 15843, LP 15849, and LP 15852 provide by Dr. Wolman GmbH, Germany were used in the study. The general description of each fungicide was taken from the Material Safety Data Sheet (MSDS) and is given in Table 4.1. Each of the four preservatives in Table 4.1 was evaluated in a screening trial at four retention levels. The most effective retention level for each preservative from this first screening trial identified and then formed the basis of the selection of second screening trial when it was combined with the retentions used in first screen trial.  Table 4.1 Type of preservatives  Trade name  Density  pH  (g/cm 3 )  LP 15842  LP 15843  LP 15849  LP 15852  Approx. 10.5 Approx. 10  Active Chemical name  ingredient (%)  0.92-0.94  Fenpropimorph  >93  Approx. 1.1  K-HDO*  30.0  Approx. 1.0  Organic fungicide  8.0  Approx. Organic fungicide 1.25 ^ 7.0 + CCTB**  94  * N-cyclohexyldiazeniumdioxy-potassium ** 2-(4-ch loropheny1)-3-cycloprophy- 1 -( 1 H- 1,2,4-triazol-1 -yl)butan-2-ol "Confidential information  4.2.3 Preparation of decay inoculum The white-rot fungus, Trametes versicolor 105E, and brown-rot fungus, Coniophora puteana 9G, were used in this experiment. Cultures of the test fungi were grown on a nutrient medium containing five weight percent malt extract and two weight percent agar. The medium was sterilized at 105 kPa for 30 minutes at 125 ° C then allowed to cool down on a laminar flow bench before inoculation (Figure 4.1). All manipulation of fungi was done under sterile conditions maintained on a laminar flow air bench. To minimize the risk of water logging the wood blocks, pre-sterilized pieces of plastic mesh with holes measuring approximately 5-7 mm 2 were placed in each disposable Petri plate. The depth of the medium was adjusted to ensure that any condensation which forms on the inside of the lid does not wet the wood samples. Petri plates containing the two test fungi were incubated at 25 ° C for two weeks before the test samples were placed on the mesh surface. - 36 -  Coniophora puteana 9G  ^  Trametes versicolor 105E  Figure 4.1 Plates after inoculation 4.2.4 Formulation and sample preparation Prior to preparing the solution of each formulation, extra samples of southern pine and yellow birch were impregnated with distilled water and acetone to determine the average solution uptake. Two different solvents had to be used as since LP 15852 and LP 15842, have a low solubility in water. They were dissolved in acetone. All other fungicides were diluted with distilled water. As expected, the solution uptake was different between southern pine and yellow birch because of the different wood structure. Based on the try out, the actual loading formulation was determined and it is outlined in Table 4.2. The amounts of each preservative which were diluted with either distilled water or acetone to produce 250m1 of the treating solution for each experiment are shown in Tables 4.3 and 4.4. After the addition of fungicides, the mixture was stirred until a uniform solution was obtained, and the mixture was used to treat six wood samples at a time by vacuum impregnation.  Table 4.2 Summarization of solution uptake  Distilled water^Acetone Species/ solution^ (g)^ (g) ^ Southern pine 1.032 (0.057)^0.706 (0.071) Yellow birch  ^  0.871 (0.028)^0.526 (0.032)  Prior to treatment all the wood blocks were oven dried (section 4.2.1) and then weighed (W 1 ). Using the uptake data shown in Table 4.2 the fungicides were diluted or dissolved in Table 4.3 to 4.5. For each solution concentration, six blocks (30 mm x 10 mm x 5 mm) were vacuumimpregnated. The blocks were placed in a beaker and a weight added to prevent them floating during treatment. The desiccator was vacuum drawn for 20 minutes, after which the solution was introduced into the desiccator. The pressure was allowed to rise to atmospheric pressure, and the blocks remained under solution for a further 5 minutes. At the end of the treatment the blocks were immediately removed from the solution and weighed (W2). The solution retention was calculated from the solution uptake (W2-W 1 ) and this multiplied by the solution concentration to provide the block retention. The blocks were then placed on a wire mesh and allowed to dry in a fume hood. Following pre-treatment all samples were sterilized for 30 minutes with steam at 105 KPa, and cooled under sterile conditions maintained on a laminar flow air bench. To achieve a moisture content of approximately 30% of each sample, samples were wetted with sterilized water. They were then exposed to actively growing, pure cultures of the preferred test fungi, cultivated in Petri dishes. Each Petri dish contained three samples and was incubated for 6 weeks at 25 ° C and 65 % RH. After 6 weeks, the test samples were removed from the petri plates. The amount of fungal - 38 -  overgrowth was noted before cleaning. The mycelium on the samples was carefully removed by brushing, taking care not to lose any wood. They were then weighed (W3) before being ovendried at 105 ° C for 24 hours and weighed again (W 4 ). The weight loss was calculated as the percentage loss of the oven-dry sample weight before (W I ) and after decay (W 4 ), compared to the original oven-dried weight (W I ) as follows:  Weight loss (%) = [(W4-W1)/W 1 ] x 100  Where, W 1 = oven-dry weight (g) before treatment; and W4 -= oven-dry weight (g) after screening trial.  The amount of chemical required to control decay, the toxic threshold is determined as the concentration of total preservative active ingredients which reduces the mass loss to less than 2%. The toxic limits are the two retention levels (the active ingredients) which include the toxic threshold. The upper retention level has a mass loss less than 2% while the lower retention has a mass loss greater then 2%. Upon completion of the first trial, the toxic thresholds were then used to create a suite of concentration for formulation based on these fungicides (Table 4.4). The toxic threshold values for each preservative was used to determine the component retention when combined with another selected preservatives based on information provided by Dr. Wolman GmbH. Table 4.4 shows the ratio of the two fungicides in each formulation. For the 1:1 ratio, each fungicide was applied at a retention level equal to 50% of the toxic threshold value. For the 3:1 ratio, the first fungicide was applied at 3/4 of the toxic threshold, while the second fungicide was applied at 1/4 of its toxic threshold.  - 39 -  Table 4.3 Active ingredients loading formulation of each fungicide "First screening trial"  Trade  Retention  Tested  Trade  Retention  Tested  Name  (g/m3)*  Fungi  , Name 1^  (g/m3)*  Fungi  50  150 White &  75 LP 15849  Brown rot  200  White rot  260  fungi  LP 15842  100 fungi 125  330  1600  50 White &  2400  Brown rot  LP 15843  75 LP15852  fungi  3600  Brown rot 100 fungi  5400  125  * in terms of active ingredient  Table 4.4 Active ingredients loading ratio for the second screening trial  Fungicide I  Fungicide II  Loading  LP 15849  LP15843  Loading  LP15842  LP15852  ratio  (50g/m3)*  (1600g/m 3 )*  ratio  (330g/m3)*  (125g/m3 )*  3:1 2:1  38 33  400 533  3:1  248  31  2:1  220  42  1^: 1  25  800  1^:^1  165  63  1:2  17  1067  1:2  1:3  13  1200  1:3  110 83  83 94  * toxic threshold value (active ingredient) was used  4.3 Results and Discussion 4.3.1 The first screening trial Table 4.5 summarizes results obtained from the first screening trial. It shows the weight loss of all treatments following 6 weeks exposure to, Trametes versicolor and Coniophora puteana. The data presented is the mean value of 6 samples prepared from each treatment and control. The values in parenthesis represent the standard deviation. Most of the test specimens at the lower retentions and controls were covered with fungal mycelium by both the white and brown-rot fungi after 6 weeks. The southern pine sapwood samples had an average weight loss of 22.09% with a standard deviation of 4.29% for C. puteana. For the white-rot fungus, T versicolor, the average weight loss for untreated yellow birch sapwood sample was 23.50% with a standard deviation of 4.77%. These results demonstrate the excellent decay capacity for all fungi under the conditions of the experiment (Figure 4.2).  Coniophora puteana 9G  ^  Trametes versicolor 105E  Figure 4.2 Petri dish of wood block before and after 1st screening test  Comparing the four preservatives, LP 15842 (94% Fenpropimorph) and LP 15852 (93% preparation based on 2-(4-chloropheny1)-3-cyclopropy1-1-(1H-1,2,4,triazle-1-yl)butan-2-ol) prevented decay by C.puteana only at the highest concentrations (Table 4.5). The three lower retentions of these fungicides failed to provide some protection, when the mass loss was compared to the control. For the white-rot fungus for LP 15842 only the highest retention (330 g/m3) prevented decay, while LP 15852, the toxic threshold was established close to the second lowest retention of 75 g/m 3 . However, the experimental data indicate that all retentions of LP 15849 (8.0 % Organic fungicide) were effective in preventing decay by both C. puteana (adjusted percent weight loss ranged from 0.20% to a maximum of 0.98%) and T versicolor (adjusted percent weight loss of 0.09% to a maximum of 0.98%). LP 15843 (30% K-HDO), which was selected due to its known excellent protection against - 42 -  brown-rot fungi, was very effective against C. puteana at all retentions (adjusted percent weight loss ranged from 0.15% to a maximum of 0.23%, but could not prevent by white-rot decay at the lowest retention (Table 4.5). From these results, it can be seen that organic fungicide showed excellent decay resistance in terms of weight loss. Miyauchi et al (2004) indicated that the amounts of such active ingredients in treated wood are specified to guarantee protection. The most obvious difference is the difference between the main cellular components of hardwoods and softwoods. The main cell type of southern pine is the tracheid, serving support as well as transport functions. Hardwoods are far more complex in this aspect, with several types of cells performing specialized functions (Hassler et al., 1999). Behr et al (1969) investigated a variety of hardwoods and softwoods treated with creosote and pentachlorophenol. One of the conclusions of their research was that, while ray tissue in softwoods was an important transport venue, it was often a hindrance to penetration into hardwoods.  ^  Table 4.5 summary of average decay rate of yellow birch and southern pine after exposure to decay fungi for 6 weeks  Trade name  ^Average Weight loss (%) Retention level ^C. puteana^T versicolor (g/m 3)* (Southern pine)^(Birch)  ^50^0.98 (0.46)^0.68 (0.25)  ^75^0.68 (0.46)^0.28 (0.14) LP 15849 100^0.07 (0.06)^0.10 (0.06) 125^0.02 (0.01)^0.09 (0.06)  ^1600^0.23 (0.17)^5.06 (5.56)  ^2400^0.22 (0.16)^0.17 (0.10) LP 15843 3600^0.20 (0.14)^0.16 (0.08) 5400^0.15 (0.05)^0.07 (0.05) 150^7.71 (4.92)^3.13 (0.50) 200^5.28 (3.21)^2.77 (0.34) LP 15842 260^5.19 (2.63)^2.73 (4.02)  ^330^0.39 (0.09)^0.20 (0.31) ^50^8.22 (2.92)^3.38 (1.87) 75^4.27 (2.92)^0.50 (0.47) LP 15852 100^2.53 (3.03)^0.46 (0.51) ^125^1.65 (1.33)^0.46 (0.22)  Control  ^  22.09 (1.39)^23.50 (2.16)  Values in parenthesis represent one standard deviation. * in terms of active ingredient +Bold number indicates the acceptable toxic threshold value from the first screening test  - 44 -  As Table 4.5 showed, no toxic threshold was determined for LP 15849 since no weight loss exceeded 2% loss. For this reason this fungicide was re-examined at lower retentions to 25% and 50% of the median retention level (50 g/m 3 ). Table 4.6 shows the mass losses for the blocks treated with the LP 15849. As mentioned earlier, the toxic threshold was determined as the preservative retention that gave a 2% weight loss. For the C. puteana, the average mass loss ranged from 1.59% to 3.86%, while for T versicolor was 2.58 to 3.47%. Since the average mass loss of both retentions exceeded the toxic threshold level for T versicolor, the lowest retention level (50 g/m 3 ) from the first screen experiment was selected for the second screening trial.  Table 4.6 summary of average weight loss  retention level ^ Trade name (g/m 3)*^  LP 15849  Average Weight loss (%) ^ C. puteana T versicolor ^ (Southern pine) (Birch)  25^3.86 (0.92)^3.47 (0.85) 37.5^1.59 (0.38)^2.58 (0.58)  * in terms of active ingredient  4.3.2 The second screening trial  Average percentage weight losses for preservative treated samples and controls exposed to T versicolor and C. puteana are presented in Table 4.7. The data represent the mean value of 6  samples prepared from each treatment group and control. The values in parenthesis represent the standard deviation. As expected, the combinations of preservatives reduced the decay rate. Presnell and Nicholas (1990) have discussed how combinations of biocides with different modes of action for controlling fungi may provide broader spectrum protection because of the possible complementation or synergism among biocides. - 45 -  Table 4.7 summary of average percentage mass loss of yellow birch and southern pine after exposure to decay fungi for 6 weeks  Average Weight loss (%) Fungicide I^ Fungicide 11 Loading ratio  LP 15849: LP 15843^LP 15842: LP 15852 C. puteana^L versicolor  (Southern pine)^(Birch)  C. puteana^T versicolor  (Southern pine)^(Birch)  3:1  0.50 (0.05)^1.96 (0.41)  0.32 (0.24)^1.88 (1.37)  2:1  0.34 (0.28)^2.50 (0.32)  2.56 (0.41)^2.32 (0.44)  1:1  0.30 (0.18)^3.30 (0.31)  2.19 (0.90)^2.30 (0.18)  1:2  0.23 (0.22)^5.86 (0.47)  2.08 (0.23)^1.44 (0.18)  1:3  0.22 (0.18)^6.39 (1.31)  0.15 (0.05)^1.29 (0.40)  Control  C. puteana  E versicolor  (Southern pine)  (Birch)  22.30 (0.95)  24.35 (1.60)  Values in parenthesis represent one standard deviation.  Fungicide 1, the combinations of LP 15849 (8% Organic fungicide) and LP 15843 (K-HDO, 30% aqueous solution), showed excellent protection against the brown-rot fungus, C. puteana. Even though the retention levels (concentration of chemical) of LP 15949 was reduced 25%-75% from toxic threshold described from the first screening trial, control of both decay fungi was achieved. However, the result against the white-rot fungus, T versicolor, in the loading ratios of 2:1 up to 1:3 (LP 15849 : LP 15843), showed this formulation to be less effective, with effectiveness decreasing, the greater the proportion of LP 15843. Only when the highest retention of organic fungicide (38 g/m 3 ) was used with the lowest retention level (400 g/m 3 ) of 30% aqueous solution of K-HDO was the toxic threshold reached. Comparing the efficacy of LP - 46 -  15843 it appears from the data that the formulation is more active against brown-rot fungus, C. puteana, since the percent weight loss of blocks tested against C. puteana are much lower than  blocks tested against T versicolor in retention levels. In the second fungicide formulation, which is a combination of LP 15852 (94% preparation based on 2-(4-chloropheny1)-3-cyclopropy1-1-(1H-1,2,4,triazle-1-y1)butan-2-ol) and LP 15842 (93% Fenpropimorph) provided protection against both type of fungi on the highest retention levels of each preservative. However, LP 15852 and LP 15842 provided slightly less protection in the intermediate (ratios of 2:1 up to 1:2).  4.4 Conclusions. Screening trails have been used to find the minimum amount of fungicide that was able to protect the impregnated samples against wood destroying decay fungi. In the first screening trial, decay resistance on sample was directly related to retention level. As the fungicide retention level increased, wood sample weight loss decreased. However, when the fungicides were combined with other selected fungicide in the second screening trial, a different pheromone was observed. The combinations of fungicides showed better performance against decay fungi than either fungicide alone. Since the combinations of fungicides with different modes of action for controlling fungi may provide broader spectrum protection because of the possible complementation or synergism among preservatives. However, the best performance result showed on the ratio of 1:3 and 3:1 which are contained the highest concentration of chemical of each preservative. Especially for fungicide I, LP15849 + LP15843, the retention level can not minimize the damage from both fungi unless the retention level of LP 15849 is above 38 g/m 3 . The results suggest that all preservatives retention level has to be highest to minimize the potential damage to wood under severe condition. This information can help to manufacture chemically-modified OSB for soil block decay testing with an adequate amount of fungicides.  Chapter 5 The influence of selected fungicides or combinations of fungicides on gelation time and viscosity of PF resin for OSB 5.1 Introduction Engineered wood composites are manufactured by applying heat and pressure during consolidation of the wood furnish (i.e., strands) which have been coated with adhesive and wax. The modern manufacturing process represents a fine balance of raw material (i.e., wood resin, wax, and other additives) in term of product performance (Wu, 2004). When manufacturing engineered wood composite materials, the addition of chemicals to the furnish can interfere with the bonding of the strands resulting in a lowering of the mechanical properties. In order to identify biocides with potential for use as a glue-line additive, the influence of the biocide (and its properties such as pH and chemical reactions) on the curing properties of the resin must be investigated ad identified. It is important to understand the basic characteristics of the resin used to manufacture OSB. PF resin is thermoset, which means it cures in the presence of heat by an irreversible crosslinking process. As temperature increases in the hot-press, the resin softens and flows into the wood surface contours. Provided the wood surface is sufficiently active, the flow of the adhesive allows intimate contact between wood and adhesive. As the temperature continues to increase, the molecular weight of the PF polymers increases due to cross-linking that occurs, viscosity increases and resin stops flowing, finally hardening and turning in to a brittle glassy solid. There are two types of PF resins; novolaks that have a formaldehyde/phenol (F/P) ratio of less than 1 and are generally made under acidic conditions, and resol resins made under basic conditions with F/P rations of greater than 1 (Frihart 2005). Most commercially available PF - 49 -  resins are water based resole PF resins. Resin flow capability is an important parameter controlling the performance of the composite panels. In general, high-flow resins develop larger bonding area and provide better panel performance as compared to the low-flow resins. However, it has been suggested that the presence of large amounts of free water would disrupt the curing reaction (Pizzi 1994). Differences in the speed of cure could be ascribed to various factors such as a) types of preservatives, b) chemical composition, c) pH levels of preservative, d) the formaldehyde to phenol (F:P) ratio, e) the pH of the adhesive mixture, and f) temperature. Changes in the viscosity and gelation time are problematic for the OSB plant. A change in viscosity, could significantly affect the flow properties of the resin on the wood furnish and its atomization as it is sprayed onto the strands. In addition, it may require modification of the equipment that supplies the resin to the spray nozzle. Changes in the gelation time, may require a change to the press time in the OSB plant. For these reasons, wood preservative and resin mixtures that change the gel time by ±2 minutes and the viscosity by ± 35 Centipoise (cPs), are deemed to be of low compatibility. The influence of adding wood preservative with the resin can be examined by measuring the change in the resin properties as they are added. Resin gelation time is considered a relative measure of the rate of resin cure. It is the time required for a resin to convert from a liquid to a solid gel. When the formulated wood preservatives are added to the resin, the active ingredients may affect the cure rate, either accelerating or retarding gelation time. The solvents can also affect the gelation time; if a solvent can not be dissipated at the right stage of cure, it will extent the gelation time, resulting in weaker bonds (Northcott et al., 1962). Viscosity is another important property of the adhesive because it influences the spread and distribution of resin on the wood strands during blending. Washout occurs when water affects the concentration and viscosity of the resin enough to weaken the adhesion to the wood strands. Therefore, if wood preservatives and the resin are to be incorporated during board manufacture, they must be - 50 -  compatible with each other. The objective of this study was to examine the compatibility of six different preservatives representing different types of fungicides with phenol formaldehyde (PF) by measuring changes in gelation time and viscosity of PF resin in order to identify desirable combination of two components.  5.2 Materials and Methods 5.2.1 Wood preservatives and Resin Six different preservatives representing different types of fungicides were provided by Dr. Wolman GmbH, Germany. The general description of each preservative taken from their Material Safety Data Sheet (MSDS) is given in Table 5.1.  Table 5.1 Preservative specifications  Active  Preservative  Trade  Density Chemical name  PH name  ingredient  (g/cm3) (%)  I  LP 15853  7.7  1.35  H  LP 16202  7.8  1.1  III  Boric acid  63  Fenpropimorph  8.3  K-HDO  10  LP 16203  6.4  1.0  Fenpropimorph  8.3  LP 15843  10.5  1.1  K-HDO +  30  LP 15849  10  1.0  Organic fungicide  8.0  LP 15849  10  1.0  Organic fungicide  8.0  LP 16203  6.4  1.0  Fenpropimorph  8.3  IV* and V**  VI  '  N-cyclohexyldiazeniumdioxy-potassium  '  Confidential information  *  Different ratio were used (LP15849:LP15843 = 3:1) Different ratio was used (LP15849:LP15843 = 6: 1)  - 52 -  Liquid phenol formaldehyde OSB resin with an approximately 59% solid content was obtained from HEXION Specialty Chemicals in Springfield, Oregon. The pH of the resin was between 10 and 11 and viscosity was between 100 and 200 centipoise (cPs). The resin was kept in a freezer prior to the measurements. Several hours before actual tests, a sufficient amount of resin was removed from the freezer, and left on the laboratory bench until its temperature reach 20 ° C before mixed with wood preservatives. 5.2.2. Preparation of formulation Each preservative was added to approximately 100g of PF resin. After the addition of the wood preservatives, formulations were prepared with vigorous hand mixing at the rate of approximately 100 rpm for 1 minute. The total weight of each formulation was approximately 100 grams. The amount of fungicide to be added to the 100g resin was calculated from the required loading of the formulated product provided by Dr. Wolman GmbH. The details of the conversion of the loading levels specified by Dr. Wolman to the concentrations of wood preservatives used here are shown in Appendix Cl.  5.2.3. Rheological measurement A controlled stress TA Instruments AR2 rheometer (Figure 5.1) was used to conduct steady state viscosity measurements with a cone geometry over a range of shear rates (0.1 sec. -1 to 550 sec. -1 ) (60mm-diameter aluminum cone, 2 degree cone angle, with 54 urn truncation gap). Flow experiments were conducted for a pure resin for the blends immediately after mixing. The steady-state shear rate was achieved by specifying a 3 percent shear rate tolerance, meaning that the stress was increased incrementally. Date was collected only after the shear rate stabilized with 3 percent or less variation. Each adhesive sample was equilibrated on the Peltier plate at 20 °  C for 1 minute before data acquisition. Three measurements were performed for each sample.  - 53 -  5.2.4 Physical measurement  Gelation time was obtained a water bath at 100 c C (212 ° F) (Figure 5.2). A test tube containing approximately 12.5 g of mixture of the preservative and resin was stirred with a glass stirring rod placed into the tube. The tube was connected to the clamp, which was then placed in the water bath. The timer was started immediately after the test tube was placed in the water bath. The solution was stirred using the glass rod at a rate of approximately 1.5 rotations per second while being heated. The time for a wood preservative/resin mixture to undergo a change from a liquid to a gel (indicated by the resin mass sticking to the rod) was recorded as the gelation time. Three measurements were performed for each sample.  Figure 5.1 Viscosity measurement  - 54 -  Figure 5.2 Gelation time measurement  5.3 Results and Discussion. Measured viscosity and gelation time for PF resin before and after adding different types of wood preservatives are described in below.  5.3.1 Viscosity and gelation time The effect of six different types of wood preservatives on PF resin was outlined in Table 5.2. The data presented is the mean value of 3 replicate samples prepared from each fungicide. The values in red number represent the standard deviation. Many studies have been done to incorporate borate chemical (the general tern associated with boron containing minerals such as borax and boric acid) as a preservative for wood composite panels bonded with phenol-formaldehyde (PF) resin often reduce resin gel time, not allowing the resin to flow and cure sufficiently. Hsu and Pfaff (1993) made panel resole type resin in a conventional hot press. The curing time and flow were reduced with the addition of boric acid. The problem is related to the functional methlylol groups on resin molecules and their interaction with borate ions (Sean et all. 1999). Even if preservative I did not caused these changes, they significantly changed the gelation time and viscosity of PF resin. Therefore, fungicide I is not suitable to mix with PF resin on glue-line treatment. An evaluation viscosity and gelation time on all concentrations (0.44%, 0.88, and 1.76% m/m) of LP15853, 63% boric acid, was not feasible because when the fungicide and PF resin was mixed it caused solids to form in the mixture (Figure 5.3).  r* -  =>  Figure 5.3 Solid formation of LP 15853  Addition of fungicide causes gradually decreases in the viscosity and an increase in the gelation time of PF resin compared to pure resin. A significant change in the gelation time and the viscosity occurred in fungicides that contained fenpropimorph as an active ingredient. Fenpropimorph is originally intended for agriculture use, and it is currently being considered for protecting wood products. As indicate in Table 5.2, all preservatives containing fenpropimorph (fungicide II, fungicide III, and fungicide VI), had a higher increase in the gelation time and a decrease in the viscosity of the PF resin when compared to other fungicides which did not contain fenpropimorph as an active ingredient. For example, fungicides containing fenpropimorph have a 15.2% — 44.2% increase in the gelation time (gelation time = 235 — 683 second), and 43.4°/0-83.9% decrease in the viscosity (viscosity = 43.7 — 95.4 Centipoise). This phenomenon may be due to either the fungicide (fenpropimorph) or the excessive water present in this formulation. Currently, there are no literature reports of the use of fenpropimorph as a - 57 -  wood preservative and its influence on the gelation time and the viscosity of PF resin.  Table 5.2 The effect of all fungicides concentration on the gelation time and viscosity of PF resin  Ave. Gelation time (Sec.) Pure resin (April 5th)  1545 (3.606)  Difference (%)  Ave. Viscosity (cPs)  109.8  0  (0.5)  Difference (%)  0 .0  LP15853- 0.44 %* LP15853- 0.88% LP15853- 1.76 °/0 Pure resin (April 5th)  LP16202- 0.13 %  11 LP16202- 0.26 °A) LP16202- 0.51 % Pure resin (April 10 th) LP16203- 0.063 °A)  111 LP16203- 0.117 "/0  LP16203- 0.234 %  1545 (3.606) 1757 (3.512) 1866 (1.528) 2080 (2.646) 1552 (3.055) 1780 (1.528) 2016 (2.517) 2228 (1.155)  109.8  0  (0.5) 57.1  13.7  (0.5)  20.8 IA 34.6  •  (0.9) 26.6 (1.5) 113.7  0  (0.5) 42.1  14.7 29.9  35.6  (0.5)  •  43.6 r•  -•  30.6 (0.5) 18.3 (0.8)  0.0  •  43.4 64.7 73.6 0.0  63.0  I l  73.1 vr 83.9  #Standard deviation in parenthesis * In terms active ingredient in board ^ indicates decrease indicates increase and  - 58 -  Table 5.2 The effect of all fungicides concentration on the gelation time and viscosity of PF resin - continued  Ave. Gelation time (Sec.) Pure resin (April 13 th )  IV ^LP 15849 : LP 15843^1852  0.027 % : 0.29 %^(4.041)  ^LP 15849 : LP 15843^2037 0.055 % : 0.58 %^(4.509)  1561 (3.512)  LP 15849 : LP 15843^1620 V  LP 15849 : LP 15843 0.027 % : 0.14 %  (2.082)  0.055 % : 0.29 %^(3.512) Pure resin (April 11 th )  1555 (2.082)  LP 16203 : LP 15849^1718 0.05 % : 0.006 %^(1.528) VI  (1.3) 98.3 (2.5) 86.1  18.7  (2.0)  30.6 ♦  LP 16203 : LP 15849^2003 0.10 % Yo : 0.012 %^(1.732) LP 16203 : LP 15849^2196 0.21 % : 0.025 %^(2.517)  68.0 (0.8) 115.6  0  (1.2)  li  112.2 .  1724^ 10.4 (2.646)  LP 15849 : LP 15843^1914  Viscosity  111.4  10.3  3.7  Ave. (cPs)  0  (1.528)  0.013 % : 0.14 %^(4.583)  0.013% : 0.072%  (%)  1560  ^LP 15849: LP 15843^1721  Pure resin (April 12` h )  Difference  (4.3) 107.0 (3.2) 100.7  22.6  (1.2) 116.4  0  (2.2)  10.5 I-  28.8 • 28.8  I 1  41.2 A  68.8 (2.1) 62.3 (1 .0)  58.6 (0.3)  Difference (% ) 0 .0  11.8  Iv  )  22.7 39.0 0.0 2.9  7.4  •  12.9 0 .0  40.9  46.5  •  11........  iv 1  49.7  #Standard deviation in parenthesis * In terms active ingredient in board ^ indicates decrease indicates increase and - 59 -  Measured gelation time for pure resin averaged 1554 seconds (Figure 5.4). As the amount of preservative increased, the gelation time gradually increased, and viscosity was decreased significantly in all tested fungicides. For example, at the 0.234% m/m application level of LP16203, the gelation time increased by over 43.6% (gelation time= 677 sec.). This obviously indicates an interaction between PF resin and fenpropimorph. In this case, none of concentrations was compatible with PF resin since their additions caused a change of more than 35 cPs in the viscosity and change of more than 2 minutes in the gelation time (Figure 5.4).  2500  120  A,  100  2000 CI)  80  ; 1500 60 1000  500 0  --M-- Gelation time (Sec.)  .111114.  .11.11••  1111  40  ■•••  A  —A— Ave. Viscosity (cPs)  20 0  Pure resin (April 10th)  LP16203 LP16203 LP16203 (0.063%m/m)^(0.117%m/m)^(0.234%m/m)  *% m/m = in board **Retentions based on active ingredients.  Figure 5.4 effect of fenpropimorph on the gelation time and viscosity compare to pure PF resin  Based on the result of gelation time and viscosity, the addition of K-HDO (Ncyclohexyldiazeniumdioxy-potassium) helped offset some of the lost gelation time and viscosity at a given fenpropimorph application levels (Figure 5.5 and Figure 5.6). Both fungicides contain 8.35% of fenpropimorph. LP 16203, without K-HDO, has a 29.9% increase in gelation time and - 60 -  a 73.1% decrease in the viscosity at 0.117% concentration, compared to the pure PF resin. However, LP 16202, with 10% of K-HDO, has only 20.8% increase in gelation time and a 64.7% decrease in the viscosity even though it had middle loading level (0.26 % concentration). It is believed that K-HDO solution helps to speed up the glue curing reaction. 35 30 6 1' 25 20 15 10 5 0  ^ LP16202 LP16203 ^ (0.117%m/m) (0.26%m/m) m/m = in board  **Retentions based on active ingredients.  Figure 5.5 Comparison of gelation time "8.35 % Fenpropimorph + 10% K-HDO vs. 8.35% Fenpropimorph"  - 61 -  0 - 10  .(0;261.)/0:iti/iti)  :•:•LP16203:•:• .................... (0; 117.% Mr.0 1) -  - 20 - 30 - 40 - 50 - 60 - 70 - 80 - 90  *% m/m = in board **Retentions based on active ingredients. Figure 5.6 Comparison of viscosity "8.35 % Fenpropimorph + 10% K-HDO vs. 8.35% Fenpropimorph"  The active ingredient in fungicide IV, fungicide V and fungicide VI are one of organic fungicide of triazole group, a new-generation organic fungicide that interferes with sterol synthesis in fungi, with a profound effect on ergosterol synthesis (Vesentini et al 2006). Addition of this organic fungicide appeared to have a pronounced effect on the viscosity and the gelation time of PF resin (Figure 5.6). At the high application level (0.234% concentration) of preservative III (8.35% fenpropimorph), the gelation time increased 43.6% and the viscosity decreased 83.9%, compared to pure resin. However, when small amount of 8% organic fungicide (0.025%) was incorporated with the retention level of fenpropimorph (0.21%) in preservative VI, the gelation time increased 41.2% and the viscosity decreased 49.6% compared to pure resin (Figure 5.7 and Figure 5.8).  - 62 -  50 40 30 20  5  10 0 LP 16203 (0.234%m/m)  LP 16203 : LP 15849 (0.21 %m/m : 0.025%m/m)  *% m/m = in board **Retentions based on active ingredients.  Figure 5.7 Comparison of gelation time "8.35% Fenpropimorph vs. 8.35% Fenpropimorph + 8% Organic fungicide" 0  j-r 1 0.203 : : (0 4  I  849 om/m)  -30  -60  -90  m/m = in board **Retentions based on active ingredients.  Figure 5.8 Comparison of viscosity "8.35% Fenpropimorph vs. 8.35% Fenpropimorph + 8% Organic fungicide" - 63 -  Fungicide V, containing 8% organic fungicide and 30% K-HDO, was the most compatible preservative for the liquid PF resin. The gelation time and the viscosity of the lowest application level were the most suitable for PF resin since their additions did not cause a change of more than 35 cPs in the viscosity and change of more than 2 minutes in the gelation time. At the lowest application level (0.085%), the viscosity decreased 3.8% (3.4 cPs) and the gelation time increased 2.9% (59 seconds). Other application levels of preservative V can also be considered because the viscosity was decreased by 7.4 (8.6 cPs), 12.9% (14.9 cPs) at 0.167 and 0.345% preservative levels, even though the change in the gelation time was more than 2 minutes (Figure 5.9). 2500 j j 2000  cg  __  -  ee  —0  9— ^  1500 h  c c 1000 C:  120 115  110 91 105  —9— Gelation time (Sec.)  500  100  Ave. Viscosity (cPs)  95 90  0 Pure resin (April 12th)  LP 15849 : LP 15843 LP 15849: LP 15843 LP 15849: LP 15843 (0.013%m/m :^(0.027%m/m :^(0.055%m/m : 0.072%m/m)^0.14% m/m)^0.29%m/m)  *% m/m = in board Retentions based on active ingredients.  Figure 5.9 The effect of preservative V on the gelation time and viscosity of PF resin  A comparison of the active ingredients shows that formulation containing organic fungicide is the most compatible with PF resin followed by K-HDO and fenpropimorph. Since most of biocides are novel for protecting wood products, there are no reports on how they effect the cure reaction of PF resin. - 64 -  5.4 Conclusion The gelation time and viscosity of liquid PF resin under influence of various wood preservatives were investigated. It was found that the LP 15853 which contains 63% boric acid was incompatible with PF resin in all application levels since they cause solids to form in the mixture as soon as it mixed. These observations indicate that they are not suitable to mix with PF resin on glue-line treatment. Changes in the viscosity and gelation time sample were directly related to fungicide concentration. As the fungicide loading level increased, the viscosity and gelation time also increased. For most of fungicides tested, the lowest concentration performed better than higher concentration. However, they were incompatible with PF resin since their additions caused changes of more than 35 cPs in the viscosity and more than 2 minutes in the gelation time, compare to the pure PF resin. Only the lowest application level of preservative V (a mixture of 0.013% organic fungicide and 0.072% K-HDO) showed good compatibility with PF resin. At 0.085% preservative level, the gelation time was increased by 3.8%, which the viscosity decreased by 2.9%. The increased gelation time and reduced viscosity was partially recovered by using organic fungicide and/or K-HDO in combination with fenpropimorph.  Chapter 6 The effects of fungicides or combinations of fungicides on mechanical properties of OSB  6.1 Introduction The incorporation of wood preservative into resin for glue-line treatment can adversely affect the mechanical properties of OSB. The modulus of elasticity (MOE), modulus of rupture (MOR) and the internal bond strength (IB) define the strength and integrity of OSB. Several reports have been discussed the effect of wood preservatives on the properties of treated wood composites. For example, Laks and Palardy (1990) found that applying spraying an emulsion of the insecticide chlorpyriphos onto flakes, bonded with 4% liquid PF and 2.5% diphenylmethane diiosocyanate adhesives adversely affected IB. Short and Lyon (1982) added a concentrated solution of copper-8-quinolinolate (oxide copper) and didecyldimethl ammonium chloride (DDAC) during the blending of furnish with 6% liquid PF resin for flakeboards made from a variety of southern hardwoods and one softwood. Oxine copper substantially reduced the IB and MOR of the boards and also adversely affect thickness swell. This was attributed to the very low pH of the oxine copper solution (Morris 1995). Inorganic waterborne preservatives generally reduce the bending strength of sawn wood by 5 to 10 percent, depending on the chemical type, retention of chemical, re-drying method, and temperature employed (Winandy 1986). Sean et al. (1999) reported that ZnB at a loading of less than 1.17% based on oven-dry furnish weight caused a slight, but not significant reduction in MOE and MOR of PF bonded OSB. Currently, there is little data on the influence of organic fungicide on the mechanical properties of components. Schmidt and Gertjejansen (1987) added triazole fungicides, during the blending after the wax and either PF or polymeric MDI resin. No adverse effects on the physical - 66 -  properties of the boards, was reported. Jeihooni et al. (1994) added powdered azaconazole during blending with 3.5% PF resin with no detrimental effect on physical properties. This objective of the research presented was to investigate the effect of the addition of selected fungicide on the mechanical properties (MOE, MOR, and IB) of OSB.  6.2 Materials and Methodology 6.2.1 Panel manufacture Dried Aspen (Populus tremuloides) strands were obtained from the Ainsworth OSB plant at 100 Mile House, BC. The strand moisture content was measured. A sample of 100 strands was randomly chosen and found to range from 4.9 to 6.7% (oven-dry basis).The dimensions of the strands varied from 5.43 mm to 118.63 mm (55.5 mm average) in length, 1.08 to 36.09 mm in width (7.39 mm average), and 0.28 to 1.84 mm in thickness (0.75 mm average). Fines were not included in the dimension measurements above. After the measurement of the MC, the strands were stored in polyethylene bags until needed. Liquid phenol formaldehyde OSB resin with an approximate 59% non-volatile content was obtained from HEXION Specialty Chemicals in Springfield, Oregon. The pH of the resin was between 10 and 11 and viscosity between 100 and 200 centipoise (cPs). Initial resin viscosity was approximately 109.8 cPs, with a maximum of 116.4 cPs by the end of use. The viscosity measurement was recorded using a controlled stress TA Instruments AR2 rheometer. The resin was kept in a freezer prior to the measurements. Several hours before actual tests, a sufficient amount of resin was removed from the freezer and allowed to thaw and was conditioned to a temperature of 20 ° C before mixed with wood preservatives. The emulsion wax with an approximately 59% non-volatile content was obtained from HEXION Specialty Chemicals in Springfield, Oregon. The preservative materials are described in Table 6.1.  ^  Table 6.1 preservatives' retention levels  Retention level*  ^  Retention level^Retention level  0.44^ 0.063^0.085 I^0.88^III^0.117^V^0.167 1.70^ 0.234^0.345 0.13^ 0.153^0.056 II^0.26^IV^0.317^VI^0.112 0.51^ 0.635^0.235 *% m/m = in board Retentions based on active ingredients  From the preliminary screening it was found that most of the fungicides were not compatible with the PF resin. Consequently, the strands were first treated with the fungicide prior to blending with the resin and wax. A known amount of furnish was weighed and placed in the blender. While the blender was running, the calculated preservative solution was sprayed onto the strands. The target retention levels for each fungicide was based on the oven-dry furnish weigh. To achieve the target preservative retention, the container of the fungicides was weighed to record the amount of solutions that had been applied during the spraying process. The strategy was based on depositing 500m1 of the fungicidal solution onto the strands. The blender was run for 10 minutes. The blender, components, was washed with warm water after each preservative treatment. After blending, the treated strands were spread on a horizontal surface on the floor and left to dry at room temperature. While the strands were drying, representative strands were measured every hour until a constant weight was reached. The increase in the weight was used to calculate the actual loading of preservative. Some strands were weighed immediately after spraying and then oven-dry to obtain an oven-dry weight from moisture content was determined. The moisture content of the strands prior to blending was about 8%. The treated and dried strands were stored in sealed plastic bags until needed. - 69 -  Several hours before actual blending, a sufficient amount of resin was removed from the freezer. The resin was thawed and placed in a water bath at 20 ° C to maintain a constant resin temperature. Each batch of treated furnish was weighed before blending with resin and wax. The resin (5% of oven dried strands) was sprayed first, after which the wax (1%) was applied. After completion of spraying, the blender continued to run for 10 minutes. After blending, the strands were removed from the blender and the batch of strands was divided by weight into an amount required for each panel and placed in sealed plastic bags. Each panel mat was randomly formed by hand inside a forming box. Two replicate panels of each loading level were manufactured. Panel pressing was accomplished with PressMan Press Control System. Pressing time was 720 seconds and pressing temperature was 190 ° C. The target density of each panel was 720 kg/m 3 . The final boards (610 x 610 x 11.5 mm) were cooled and conditioned in a conditioning chamber maintained at 22 ° C and 65% relative humidity (RH) prior to testing.  6.2.2 Mechanical property study  A total number of 38 panels were prepared to assess the mechanical testing properties as well as the durability with respect to decay. Replicate panels were produced for each fungicide and retention. The rough boards were trimmed to 533 by 533 mm in size. Specimens for strength and durability were cut from the same location in each panel (Figure 6.1). Specimen dimensions were measured with digital calipers prior to testing. Implicate measurements of the width and thickness of the static bending (MOE/MOR) samples were made and recorded. Average values of each of the dimensions were used for the sample size in calculating property values. Four unaged replicates (339.45 x 76.45 x 11.58 mm) from each panel were prepared from each strandboard for testing. A total of 152 MOE/MOR specimens were prepared for static bending testing. The static bending test samples were evaluated in 3-point bending using a Sintech 30D test machine (Figure 6.2) according to the ASTM standard D-1037 (ASTM 1999). The span for - 70 -  each specimen was 276 mm. The samples were loaded at the center of the span with the loading speed of 5.52 mm/minute applied to the face at a constant rate. The maximum load, modulus of rupture and modulus of elasticity were recorded. Twelve replicates (51.28 x 51.20 x 11.60 mm) were cut from each strandboard. A total of 456 TB specimens were prepared for the evaluation in accordance with the ASTM D-1037 (ASTM  1999). These specimens were then conditioned for one week to attain constant moisture content (12%) in a conditioning chamber maintained at 20 ° C and 65 percent relative humidity (RH). Internal Bonding (IB) specimens were measured for length, width, and thickness, and weighed prior to bond to a 50 mm square aluminum base plate with hot melt glue. Each sample was attached to the MTS testing machine. The specimens were pulled by separation of the heads of the testing machine until failure. IB strength was calculated based measured peak load and sample cross-section area. The crosshead speed of the testing machine was 4.57 mm/ minute (Figure 6.3).  Figure 6.1 Cutting pattern diagram - 71 -  6.2.3 Statistical analysis  Statistical comparisons were based on a one-way analysis of variance (ANOVA) using the software JMP IN version 4.0.3 (SAS Institute Inc.). The test examined the effects of wood preservation level and wood preservative type on MOR, MOE, and IB. Tukey-Kramer significant difference multiply-range test at the 5 percent significance level was used to compare the difference among treatment means.  Figure 6.2 MOE/MOR testing  Figure 6.3 Internal bonding testing - 72 -  6.3 Results and discussion Based on a one-way ANOVA, there was a distinct difference (at the 5.0% significance level) for bending properties along samples from outer parts and inner parts of the board. Sumardi et al (2007) discussed how the mechanical properties of OSB are affected by both layer structure and density. Figure 6.4 showed the example of outer (a) and inner (b) part sample from panel. Samples from outer part had more strands aligned parallel (i.e. <30 degree off the long axis) to the length of the specimen. Compared to the outer sample, the strands of the sample from the inner part of the board showed less uniform alignment in any direction. It is believe that the reason of distinct difference for bending properties along specimens from outer and inner parts of panels were affected by layer structure because when the panels were randomly formed by hand, strands tended to oriented parallel to the edge of forming box to prevent the blowing or delamination during the hot pressing. All panels also had relatively uniformed density profiles for both outer and inner parts. Table 6.2 shows the density profiles for both outer and inner parts. Therefore, each static bending property (MOE and MOR) was compared internally and with the control values to determine the effect of preservative retentions on the property. Data for samples removed from the outer and inner board locations were compared separately, due to the difference in their properties based on the location in the board.  Table 6.2 Average density profiles of specimens from both outer and inner part of panels  Outer^  Inner  742 kg/m 3^733 kg/m 3 ^ (35.34) (35.27)  - 73 -  Figure 6.4 Example of outer (a) and inner (b) part sample from panel  6.3.1 Static bending properties Static bending properties (MOE/MOR) for boards containing various organic preservatives added as a pre-treatment of the strands are summarized in Tables 6.3. Samples treated with organic preservatives at all concentration levels, showed no significant differences in density, when compared to untreated controls. Their density ranged from 724.67 kg/m 3 for preservative IV at 0.235% of application level to 747.01 kg/m 3 for preservative II at 0.510% of retention level. A statistical analysis of both the MOR and MOE of both outer and inner samples showed that there was no significant difference in from board treated with all retentions of preservative II and III that contain fenpropimorph as the major active ingredient when compared to untreated strandboard. However, samples treated with other organic preservatives at higher concentration levels, showed significant differences in MOR and MOE, when compared to control samples (Table 6.2) The results of the static bending properties are summarized in Appendix D1 to D6.  - 74 -  Table 6.3 Static bending properties of treated OSB  Treatment  Density (kg/m 3)  MOE (GPa) Outer  737.32 (3.08) 730.61 (8.80) 730.13 (7.86) 729.38 (3.58)  8.14 (0.27) 7.10 (0.70) 6.98 (0.44) 6.66 (0.77)  Control  737.32 (3.08)  8.14 (0.27)  P-Il (0.13%) P-H (0.26%) P-II (0.51%)  730.56 (4.60) 741.84 (2.47) 747.67 (0.93)  7.19 (0.61) 7.07 (0.45) 7.09 (0.77)  737.32 (3.08) 738.76 (18.29) 731.52 (0.57) 743.83 (19.58)  8.14 (0.27) 7.30 (1.07) 6.88 (0.40) 6.74 (0.75)  Control P-I (0.44%) P-I (0.88%) P-I (1.76%)  Control P-III (0.063%) P-III (0.117%) P-III (0.234%)  MOR (MPa)  Inner  A A A B A A A A A A A A  Outer  5.47 (0.34) 5.03 (0.66) 5.34 (0.42) 4.94 (0.96)  37.10 (7.14) 35.09 A (3.65) 34.71 A (4.46) 28.83 A (2.14)  5.47 (0.34) 5.48 (1.18) 4.74 (0.47) 5.47 (0.96)  37.10 (7.14) 35.10 A (1.49) 32.79 A (2.84) 30.39 A (5.65)  5.47 (0.34) 5.36 (0.56) 5.26 (0.83) 4.85 (0.68)  37.10 (7.14) 36.31 A (6.43) 26.99 A (3.99) 26.32 A (2.91)  A  A  A  Inner  A A A A A A A A A A A A  23.77 (1.59) 23.56 (3.54) 26.32 (5.93) 26.60 (4.29) 23.77 (1.59) 23.52 (6.79) 21.44 (1.72) 26.81 (2.46) 23.77 (1.59) 23.66 (7.23) 22.53 (4.18) 22.46 (5.43)  A A A A A  * Standard deviation in parenthesis **Values within each preservative and variable that have a common letter are not significantly different at significance level of p=0.05  Table 6. 3 Static bending properties of treated OSB- continued  Density  MOE (GPa)  (kg/m 3 )  Outer^Inner  MOR (MPa)  Treatment  Control P-IV (0.153%) P-IV (0.317%)  737.32 (3.08) 736.57 (7.58) 729.80 (0.69)  P-IV (0.635%)  757.61 (9.80)  Control  737.32 (3.08)  P-V (0.085%) P-V (0.167%) P-V (0.345%) Control P-VI (0.056%) P-VI (0.112%) P-VI (0.235%)  718.32 (9.85) 733.32 (2.78) 727.70 (9.96) 737.32 (3.08) 731.16 (13.66) 737.02 (4.72) 724.67 (2.04)  8.14 (0.27) 6.56 (0.60) 6.02 (0.62) 6.83 (0.53)  A B B B  8.14 (0.27) 7.30 (0.90) 6.03 (0.50)  A  5.66 (0.47)  B  8.14 (0.27) 7.66 (0.66) 6.84 (0.87) 6.56 (0.81)  A  B  A A A B  5.47 (0.34) 54.98 (0.64) 4.58 (0.70) 4.55 (0.52) 5.47 (0.34) 5.22 (0.50) 5.61 (0.37) 4.41 (0.19) 5.47 (0.34) 5.60 (0.53) 4.71 (0.57) 4.88 (0.58)  Outer^Inner  A A A  37.10 (7.14) 33.17 (2.58) 28.08 (7.86)  A A A  23.77 (1.59) 21.16 (3.45) 19.03 (1.72)  A  28.30 (5.28)  A  20.54 (3.72)  A  37.10 (7.14)  A  23.77 (1.59)  A A B  A A A A  30.59 (4.09) 29.59 (5.77) 23.85 (3.25) 37.10 (7.14) 34.87 (6.83) 30.57 (5.73) 29.63 (2.78)  A A B  A A A A  24.79 (1.38) 24.04 (4.15) 19.16 (3.64) 23.77 (1.59) 27.39 (5.60) 19.06 (3.83) 18.42 (4.36)  A A A B  * Standard deviation in parenthesis **Values within each preservative and variable that have a common letter are not significantly different at significance level of p=0.05  - 76 -  The fungicide, preservative 11 (8.35% fenpropimorph and 10% K-HDO), shows that the fungicide treatment did not affect the static bending strength. These results were also consistent with previous finding obtained with waferboards, where the pre-treatment of strands with wood preservatives such as 8.35% fenpropimorph and 20% of K-HDO, did not have a significant negative effect on the static bending properties (Fang 2004). In a comparison of preservative VI, other OSB prepared from strands treated with the fenpropimorph as the major active ingredient, shows that static bending properties decreased with the increase of retention levels. A relatively high reduction MOE and MOR occurred in outer sample and inner sample at 0.235% retention level. However, when organic fungicide was added to fenpropimorph the mechanical properties appeared to be offset some of the lost mechanical properties of sample treated with fenpropimorph alone. 36.31 MPa^34.87 MPa  50  37.10 MPa  40  30  20  10  7.30 GPa  7.66 GPa  .^•  8.35% fenpropimorph (0.063%)^8.35% fenpropimorph (0.10%) 8% organic fungicide (0.012%)  Control MOE (GPa) 0 M OR(M Pa)  * Error bar indicates standard deviation Figure 6.5 Comparison of mechanical properties "8.35% Fenpropimorph + 8% organic fungicide vs. 8.35% Fenpropimorph For example, at the 0.112% retention level (0.10% of fenpropimorph and 0.012% of organic - 77 -  fungicide) of preservative VI, the maximum MOE and MOR values were 7.66 GPa (5.9% decrease) and 34.87 Mpa (6.0% decrease) for outer sample, and 5.6 GPa (2.4% increase) and 27.39 Mpa (15.2% increase) for inner sample. However, even with the less amount of solution, preservative III (0.063% fenpropimorph) had 7.30 GPa (10.3% decrease) and 36.31 Mpa (2.13% decrease) for outer sample, and 5.36 GPa (2.01% decrease) and 23.66 Mpa (0.5% decrease) for inner sample compare to untreated sample (Figure 6.5). Similar results were obtained at the higher retention levels. Contrary to expectations, boric acid, which exhibited incompatibility with liquid PF resin at all concentrations because of solid formation when it was mixed with resin, showed satisfactory performance in mechanical properties. A statistical analysis of both the MOR and MOE of both outer and inner samples showed that there was no significant difference in from board treated with two lower retentions when compared to untreated strandboard. Except for the highest retention level (0.176%m/m), MOE values of outer samples had 18.5% reduction (Figure 6.6).  50  37.1 MPa 35.09 MPa  40  34.71 MPa 28.83 MPa  30 20 10  8 14 GPa  control^0.44  ^  0.88  Target loading level (% m/m)  1.76 ES) MOE (GPa) 0 MOR (MPa)  * Error bar indicates standard deviation Figure 6.6 Comparison of mechanical properties of boric acid - 78 -  The pre-treatment of the strands with a mixture of organic fungicide and K-DHO relatively high reduction MOE of outer sample compared to untreated OSB sample (Figure 6.7) As indicated in Figure 6.6, the decrease in mean MOE of outer sample ranged from 10.3% (Preservative V at 0.085% level) to 30.5% (Preservative V at 0.345% level) compared to the untreated OSB. However, the MOE and MOR of inner, and MOR at the lower retentions of outer sample were not significant affected by mixing a mixture of organic fungicide and K-DHO with the PF resin. No explanation can be given for this anomaly at this time. 9  N  6 c71  a, C.7 O  3  0 0^0.085^0.153^0.167^0.317^0.345^0.635 Target loading level (% m/m) Figure 6.7 Comparison of MOE "8% organic fungicide + 30% K-DHO"  6.3.2 Internal Bond (IB) properties Statistical analysis for IB strength property found that IB strength of treated samples was directly related to retention level. The results of the IB are summarized in Appendix D-D7. As the preservative loading level increased, IB values decreased significantly (Table 6.4). In this -79-  study, the IB for boards produced from treated strandboard did not achieve the minimum requirements of the CSA 0437 standard, where minimum internal bond strength of 0.345 MPa is required. The lowest IB strength was recorded for boards made from strand pre-treated with the highest retention levels preservative IV which contain 8% organic fungicide and 30% K-HDO in the ratio. The IB reduced by 43.17% compared to the untreated controls. Preservative II and III, which did not have a significant negative effect on the static bending properties, caused at least a 26.3% and 38.3% decrease in IB strength. Lower IB strength for boards prepared for treated strands could be attributed to chemical residues, which may interfere with the bonding wood and PF resin. Alternatively surface-active agents in the preservative, may cause PF resin to over-penetrate the wood (Vick 1990). Increasing moisture content of strands introduced from an emulsified aqueous solution, can cause washout of the resins, and reduce the bonding.  Table 6.4 IB properties of treated strandboard  lB (MPa)  Control P 1-(0.44%) P I-(0.88%) P I-(1.76%) Control P H-(0.13%) P II-(0.26%) P 1140.51%) Control P 11140.063%) P III-(0.117%) P 11140.234%)  0.410 (0.039)* 0.353 (0.056) 0.283 (0.069) 0.299 (0.073) 0.410 (0.039) 0.312 (0.077) 0.302 (0.086) 0.346 (0.060) 0.410 (0.039) 0.253 (0.070) 0.269 (0.061) 0.304 (0.082)  lB (MPa)  A  Control  B  P IV-(0.153%)  C  P IV-(0.317%)  C  P IV-(0.635%)  A  Control  B  P V-(0.085%)  B  P V-(0.167%)  B  P V-(0.345%)  A  Control  C  P VI-(0.056%)  B  P VI40.112%)  B  P VI-(0.235%)  0.410 (0.039) 0.348 (0.053) 0.302 (0.063) 0.233 (0.066) 0.410 (0.039) 0.291 (0.058) 0.316 (0.061) 0.244 (0.052) 0.410 (0.039) 0.380 (0.058) 0.280 (0.056) 0.284 (0.065)  A B C D A B B C A A B B  * Standard deviation in parenthesis Values within each preservative and variable that have a common letter are not significantly different at significance level of p=0.05  The overall mechanical properties values on tested wood preservatives are summarized in Table 6.5. A common letter in each category indicate that values are not significantly different at a significance level of p=0.05 within the category. - 81 -  Table 6.5 Mechanical properties of treated strandboard  MOR  MOE  Preservative  Control P140.44%) P 140.88%) P 141.76%) P 1140.13%) P II40.26%) P II40.51%) P 11140.063%) P 11140.117%) P 11140.234%) P 1V40.153%) P 1V40.317%) P 1V40.635%) P V-(0.085%) P V-(0.167%) P V-(0.345%) P VI40.056%) P VI40.112%) P VI40.235%)  IB outer  inner  outer  inner  A* A A B A A A  A A A A A A A  A A A A A A A  A A A A A A A  A B C C B B B  A A A B B B A B B A A B  A A A A A A A A B A A A  A A A A A A A A B A A A  A A A A A A A A A A A B  C B B B C D B B C A B B  *A common letter are significantly different at significance level (p=0.05) Values within each preservative and variable that have a common letter are not significantly different at significance level of p=0.05  6.4 Conclusion  There were no indications that most of the panels produced from strands treated with fungicide or combinations of fungicides were weaker than untreated panels in terms of bending (MOR) and stiffness (MOE) (P=0.05). All static bending test values for the both control samples and samples from boards with strands produces with fungicide or combinations of fungicides exceeded the minimum CSA 0473 requirement of 3103 MPa (3.103 GPa) and the minimum CSA requirement of 17.23 MPa for MOR. The addition of preservatives strands prior to board production showed a negative effect on the internal bonding strength. Most of samples from treated boards did not meet the minimum CSA 0473 requirement of 0.345 MPs. The effects varied with type of preservative and application levels. The greatest reduction mechanical properties occurred at the highest retention levels of preservative V, which contain 6 : 1 ratios of 8% organic fungicide and 30% K-HDO as active ingredient, had a significant difference compared to untreated strandboard. For example, preservative V, the incorporation this preservative caused a maximum 30.5% reduction in MOE and 35.7% reduction in MOR of outer sample, and a maximum 19.4% reduction in MOE and 19.4% reduction in MOR of inner sample. Although the mean IB values were 40.5% drop compared to untreated OSB. However, the adverse effect of preservative on IB strength may possible be minimized by the application of more PF-resin or addition of organic flowing agent containing hydroxyl (-OH) groups such as polyethylene glycol (PEG).  Chapter 7 Decay resistance properties of OSB produced from strands pretreated with fungicides or combinations of fungicides  7.1 Introduction Wood decay basidiomycetes fungi, are probably the most destructive biological pathogens on wood structures because they can cause rapid structure failure. There are two types of wood decay fungi encountered by homeowners: brown-rot fungi and white-rot fungi. In general, the brown-rot fungi cause more degradation and greater weight loss than the white-rot fungi. Brownrot fungi, rapidly depolymerize cellulose and hemicellulose, and degradation products are produced faster than they are utilized (Cowling 1961). The rapid depolymerisation of the wood carbohydrates is reflected by the substantial increase in alkali solubility products and the rapid decrease in strength properties of brown-rotted wood (Green III and Highly 1997). Curling et al (2001) reported that the mass loss was hardly measurable for an approximate 40% loss in MOR, and occurred in a relative ratio of 4:1 bending strength/mass loss. As decay progresses, brownrot fungi degrade the polysaccharide components, cellulose and hemicellulose. The loss of polysaccharides is first seen in the S2 layer of the secondary cell wall (Blanchette at al, 1900). This layer has a comparatively lower lignin concentration than the Si and S3 layers, possibly making the polysaccharides more accessible to degradation (Daniel 1994). In advanced stages of brown-rot, wood becomes friable and splits appear across the grain. White-rot fungi can attack all the major wood components, cellulose, hemicelluloses and lignin, simultaneously, and causes wood to feel soft, spongy, and to appear bleached. Wood affected by white-rot fungi normally does not crack across the grain, but develops an abnormal shrinkage or collapse when severely degraded. The losses in strength are generally lower than - 84 -  those occurring in wood rotted by brown-rot fungi, typically ranging from 10 to 30 percent. Toughness can however decrease dramatically to losses of 70 percent in hardwoods with only 4 percent mass loss (Eaton and Hale 1993). The degree of susceptibility to attack by decay fungi varies among wood species. Some wood species with a high degree of natural durability such as cedar have been added to OSB furnish to improve the durability of flakeboard (Haataja and Laks 1995). However, a decline in the availability of naturally durable timber species, and their increased cost to consumers, has resulted in a greater use of preservative chemicals to protect less durable timber (Humphris et al. 2001). Boards prepared from strands pretreated with one of six preservative formulations were prepared for this study. The Preservatives were preservative I (boric acid); preservative II (a mixture of fenpropimorph and K-HDO); preservative III (fenpropimorph), preservative IV and V (a mixture of organic fungicide and K-HDO); and preservative VI (a mixture of fenpropimorph and organic fungicide). The intention of this study was to evaluate the efficacy of different preservatives both brown and white-rot fungi using the North America soil block method (AWPA E10-06).  7.2 Materials and Methodology 7.2.1 Wood and decay fungi preparation Experimental materials for the decay resistance test were obtained from the panels prepared as described in Table 6.1. For reference, commercially produced OSB containing zinc borate (0.83%) from Weyerhaeuser mill was used. In order to observe any effects of the phenol formaldehyde residue in the strandboard, the extent of decay was measured in untreated southern pine sapwood blocks exposed to selected brown-rot fungi and untreated poplar sapwood blocks exposed to white-rot fungi. All specimens were tested according to AWPA E10-06 (AWPA 2007) using cultures two brown-rot fungi: Gloeophyllum trabeum Pers. Ex Fr. (Madison 617, ATCC 11539) and Postia placenta (Fries) M. Larsen et Lombard (Madison 534, ATCC 11538), and two white-rot fungi: Trametes versicolor (L. ex Fr.) Pliat (FP-101664-Sp., ATTC42462) and Irpex lacteus (Fr.) (Madison 517, ATTC 11245). Cultures of test fungi were obtained from Forintek Canada Corp. in Vancouver, Canada.  7.2.2 Decay resistance study The fungi were cultured on a nutrient medium containing 2 percent malt extract and 1.5 percent agar by weight. When they had grown well on the plate a small plug containing fungal inoculum was removed and placed on malt extract agar (MEA) in freshly prepared and sterilized at 105 KPa for 30 min at 125 ° C. The petri plates of the four test fungi were incubated at 25 ° C for two weeks prior to inoculating the soil jars. Clean 450 ml culture jars were carefully prepared as follows. Distilled water (43 ml ± 1 ml) was added to each jar followed by sterilized potting soil (180g ± lg of soil). The soil has been prepared by screening through a U.S. No. 6 sieve to remove large particles and break the lump soil. A pine sapwood feeder strip (60 x 26 x 3 mm) - 86 -  was placed on the surface of the soil of those culture jars being inoculated with the for brown-rot fungi. For culture jars receiving white-rot fungi, a poplar feeder strip of similar dimensions was placed on the surface of the soil. The culture jars were covered loosely with a plastic lid and autoclaved (45 min with steam at 103. KPa), followed by a second autoclave cycle to kill all soil bacteria and spores. After cooling the jars on a laminar flow bench the soil jars were then inoculated under sterile conditions with the test fungi. After inoculation, the plastic cap of each jar was immediately replaced by a sterilized metal screw lid with a small hole (approximately 3 mm diameter) sealed with a Gelman 0.2 micron metrical autoclavable filter (25mm in diameter). Each inoculated jars was the incubated at 25 ° C at 65% RH for three weeks until the feeder strip was heavily colonized by the test fungus. Two identical (same preservative and retention) sterilized wood cubes (19 x 19 x 11.5 mm) were then placed on top of each colonized feeder strip. The soil jars were incubated for 12 weeks at 25 ° C and 65% RH. At the end of the 12 weeks exposure, the test blocks were removed from the soil jars and the mycelium covering the block surfaces was carefully removed by brushing. They were then weighed before being oven dried at 103 ° C ± 2 overnight and re-weighed to provide a final oven dry mass. Extra soil jars containing untreated controls, which were used to confirm the fungal activity, were incubated with other soil jars in each incubator. To estimate the toxic threshold application level of each preservative, a lower limit of 3% was determined, as required by the AWPA standard. A weight loss of less than 3% is normally regarded as effective control of decay in such tests (Morris 1995), since it is that small mass losses of up to 3% can occur due to loss of soluble components in wood extractions during experiment.  7.2.3 Statistical analysis Statistical analysis based on a one - way analysis of variance (ANOVA) using the software JMP - 87 -  IN version 4.0.3 (SAS Institute Inc.) was performed to test the effects of each wood preservation and its concentration on the decay resistance to each fungus. A Turkey-Kramer's test was conducted after the analysis of variance to determine the differences among the means. The statistical analysis the level of confidence was 95%.  7.3 Results and discussion 7.3.1 Decay resistance properties Average mass losses of blocks from boards prepared from strands pretreated with each of six preservatives, together with blocks from untreated boards exposed to brown-rot (Gloeophyllum trabeum and Postia placenta) and white-rot (Trametes versicolor and Irpex lacteus) fungi are  presented in Tables 7.1a and 7.1b. The detail ANOVA data are summarized in Appendix El to E4. The data presented is the mean value of 12 blocks, (6 blocks prepared from each replicate of board). The value in parenthesis represents the standard deviation. The mass losses for the untreated blocks demonstrate excellent decay capacity for all tested decay fungi under the laboratory condition. The untreated samples were covered with fungal mycelium in both brown and white-rot culture bottles after 12 weeks exposure (Figure 7.1). The final moisture content of the blocks varied from 34.38% to 62.05%. The southern pine sapwood blocks had an average 47.30% mass loss (4.42% standard deviation) for P. placenta and 43.19% mass loss (3.57% standard deviation) for G. trabeum. For white-rot fungi, the average mass loss of poplar sapwood was 38.74% (2.95% standard deviation) against T versicolor and 46.24% (7.07% standard deviation) against 1. lacteus. Similar excellent mass losses were obtained for the untreated OSB. In this case, the aspen OSB blocks had an average 36.22% mass loss (4.86% standard deviation) for P. placenta and 29.59% mass loss (3.57% standard deviation) for G trabeum. For white-rot fungi, the average mass loss of poplar sapwood was 24.74% (2.67%  standard deviation) against T versicolor and 35.72% (3.95% standard deviation) against I. lacteus (Figure 7.2). While the mass losses are excellent, they are slightly lower than the solid  wood samples. The results reveal the effects of residual phenol formaldehyde. The influence of wax on the MC can be discounted since the MC of the OSB is similar to that of the solid wood. Schmidt and co-workers (1978) have suggested that PF resin residue may confer some enhanced - 89 -  durability to particleboard resistance because of its high pH and the presence on non-condensed phenol. However, while these volatile compounds might affect laboratory test, they are unlikely to affect the in-service durability (Cockroft 1978).  1. lacteus  ^  G. trabeum  Figure 7.1 Southern pine sapwood after 12 weeks of exposure to white and brown-rot fungi  Table 7.1a Average mass loss after 12 weeks of exposure to both brown-rot fungi M.L (%)  MC (%)  P. placenta  47.30 (4.42)  52.96 (5.94)  G. trabeum  43.19 (3.57)  50.04 (4.74)  P. placenta  36.33 (4.86)  56.69 (11.38)  G. trabeum  29.59 (3.57)  57.81 (5.60)  0.83% ZnB  P. placenta  2.03 (0.48)  40.30 (2.63)  (OSB)  G. trabeum  1.90 (0.18)  38.28 (3.45)  Control (Southern pine sapwood) Control (OSB)  M.L (%) PI-1 (0.440%) PI-2 (0.880%) PI-3 (1.760%) PII-1 (0.130%) PII-2 (0.260%) PII-3 (0.510%) PIII-1 (0.063%) PIII-2 (0.117%) PIII-3 (0.234%)  MC (%)  M.L (%)  MC (%)  1.50 (0.82)  40.52 (3.97)^PIV-1  1.82 (0.81)  46.12 (3.55)  G. trabeum  2.05 (1.17)  51.99 (5.45)^(0.153%)  1.95 (0.30)  45.61 (4.57)  P. placenta  1.00 (0.54)  48.69 (4.01)^PIV-2  1.24 (0.48)  45.33 (7.03)  G. trabeum  0.68 (0.84)  52.56 (6.52)^(0.317%)  1.48 (0.54)  49.03 (3.63)  P. placenta  0.88 (0.64)  42.68 (5.68)^PIV-3  0.82 (0.41)  40.22 (3.78)  G. trabeum  0.14 (0.08)  48.23 (5.86)^(0.635%)  1.25 (0.21)  43.57 (6.24)  P. placenta  1.92 (0.63)  47.82 (5.58)  2.28 (1.20)  48.25 (5.20)  G. trabeum  3.10 (2.62)  42.17 (5.48)  1.39 (0.46)  44.50 (5.51)  P. placenta  1.82 (0.21)  42.87 (6.89)^PV-2  1.48 (0.35)  44.94 (6.02)  G. trabeum  2.09 (0.86)  48.09 (8.31)^(0.167%)  0.85 (0.51)  44.91 (8.37)  P. placenta  1.78 (0.19)  42.08 (3.42)^PV-3  0.67 (0.32)  44.23 (7.37)  G. trabeum  1.66 (0.62)  40.43 (6.77)^(0.345%)  0.48 (0.38)  47.35 (6.00)  P. placenta  1.95 (0.60)  49.37 (8.12)^PVI-1  5.13 (3.05)  46.59 (4.69)  G. trabeum  3.31 (1.59)  37.12 (8.96)  2.59 (0.88)  42.15 (4.33)  P. placenta  1.77 (0.32)  48.56 (7.16)^PVI-2  1.63 (0.50)  42.24 (6.75)  G. trabeum  2.21(0.81)  47.46 (5.15)^(0.112%)  1.63 (0.80)  47.45 (6.73)  P. placenta  1.96 (0.22)  45.76 (5.89)  PVI-3  0.53 (0.41)  45.33 (4.27)  G. trabeum  1.54(0.71)  49.43 (5.49)  (0.235%)  1.44 (0.60)  42.80 (5.76)  P. placenta  PV-1 (0.085%)  (0.056%)  *Number in parenthesis indicates standard deviation  - 91 -  Table 7.1b Average mass loss after 12 weeks of exposure to both white-rot fungi  M.L (%)  MC (%)  T. versicolor  38.74 (2.95)*  62.05 (3.61)  1. lacteus  46.24 (7.07)  58.65 (4.06)  T. versicolor  24.74 (2.67)  53.12 (4.07)  I. lacteus  35.72 (3.95)  55.46 (7.14)  T. versicolor  1.90 (0.38)  39.21 (3.57)  I. lacteus  2.11 (0.52)  38.90 (2.05)  Control (Poplar sapwood) Control (OSB) 0.83% ZnB (OSB)  PI-1 (0.440%) PI-2 (0.880%) PI-3 (1.760%) PII-1 (0.130%) PII-2 (0.260%) PII-3 (0.510%) PIII-1 (0.063%) PIII-2 (0.117%) PIII-3 (0.234%)  M.L (%)  MC (%)  piv-i  1.77 (0.62)  42.82 (4.40)  48.85 (4.67)  (0.153%)  1.57 (0.32)  44.34 (4.02)  1.23 (0.80)  50.03 (5.41)  PIV-2  1.72 (0.52)  45.06 (5.28)  I. lacteus  3.58 (1.16)  50.89 (5.02)  (0.317%)  1.56 (0.28)  46.45 (4.11)  T. versicolor  0.80 (0.43)  48.21 (5.85)  PIV-3  1.19 (0.63)  51.46 (5.51)  I. lacteus  0.36 (0.50)  47.97 (5.13)  (0.635%)  0.68 (0.41)  45.31 (5.90)  T. versicolor  4.41 (1.73)  46.99 (8.16)  PV-1  2.07 (0.59)  46.97 (4.00)  1. lacteus  15.2 (2.18)  34.38 (8.84)  (0.085%)  1.71 (0.54)  50.37 (3.67)  T. versicolor  3.56 (1.47)  49.23 (6.79)  PV-2  1.31 (0.67)  44.75 (7.86)  I. lacteus  10.92 (2.52)  35.13 (8.62)  (0.167%)  1.52 (0.50)  46.94 (3.81)  T. versicolor  2.43 (0.75)  48.08 (3.23)  0.96 (0.88)  45.51 (4.76)  1. lacteus  9.46 (1.49)  39.65 (5.24)  (0.345%)  1.40 (0.29)  45.39 (4.26)  T. versicolor  5.01 (3.95)  46.31 (8.14)  PVI-1  4.18 (1.06)  46.35 (2.73)  I. lacteus  7.25 (2.61)  37.12 (9.32)  (0.056%)  3.49 (0.40)  46.76 (5.61)  1 versicolor  2.30 (0.95)  47.96 (4.14)  PVI-2  2.05 (0.53)  44.44 (3.65)  1. lacteus  6.10 (2.25)  40.56 (3.34)  (0.112%)  2.22 (0.69)  46.86 (4.03)  T. versicolor  1.80 (1.13)  46.47 (11.26)  0.49(0.37)  44.30 (7.72)  I. lacteus  2.47 (1.13)  51.93 (5.00)  1.06 (0.63)  41.75 (4.74)  M.L (%)  MC (%)  T. versicolor  1.36 (0.73)  48.88 (5.33)  I. lacteus  4.88 (0.81)  T. versicolor  PV-3  PVI-3 (0.235%)  *Number in parenthesis indicates standard deviation  - 92 -  60 50  10  Pine  ^  Poplar  ^  Control (OSB)  0 P. Placenta El G. trabeum EB 7'. versicolor 0 1. lacteus Figure 7.2 Decay resistances of untreated test blocks  Zinc borate treated OSB have been evaluated in laboratory soil block tests against pure culture of brown and white-rot fungi with good results (Lee 2003, Fang 2004). The addition of 0.83% zinc borate into strandboard effectively prevented decay. The average mass loss of zinc borate treated strandboard exposed to brown-rot fungi ranged from 2.03% (P placenta) and 1.90% (G trabeum). For white-rot fungi, the mass losses were 1.90% (T versicolor) and 2.11% (1. lacteus).  All mass losses are well below the minimum mass loss of 3%. The decay resistance mechanism of borate chemicals is not well known. Weight loss in OSB prepared from pretreated strands treated was directly correlated to the chemical retention and the fungal type. A low treatment retention related in a higher mass loss in most of preservatives. For example, strand pretreated with preservative VI (a mixture of fenpropimorph and organic fungicide) blocks, showed 1.06% mass loss against I. lacteus and 0.53% weight loss against P. placenta at the highest preservative retention (0.235%). However, - 93 -  at the lowest retention level (0.056%), it had 3.49% weight loss against I. lacteus and 5.13% mass loss against P. placenta. The pretreated of strands with a preservative solution (P - I) containing of boric acid showed that not even the highest initial loading of boric acid was sufficient to completely control both brown-rot and white-rot fungus. Based on a mass loss of less than 3%, being regarded control of decay, the toxic threshold of boric acid treated strandboard was achieved at a target loading of 1.76% of preservative I against both types of decay fungi (Figure 7.3), while even the lower retention of 0.440% controlled both brown-rot fungi.  Toxic thresholds ZnB lacteuA)^ZnB (P. Placenta) ZnB (T. versicolor)^ZnB (G. trabeum)  0.440^0.880^1.760^0.83% ZnB  Taget active ingredient content (%) —0-- P. Placenta^- o - G. trabeum  —  A—  T. versicolor^1. lacteus  o ZnB (P. Placenta)^0 ZnB (G. trabeum)^A ZnB (T. versicolor) ^ ZnB (I. lacteus)  Figure 7.3 Average mass losses of Preservative I due to decay fungi  The pretreated of strands with a mixture of organic fungicide and K-HDO showed an excellent protection against fungal attack on wood components (Figures 7.4 and 7.5). Currently, no research has been done using a mixture of organic fungicide and K-HDO treated OSB against both types of decay fungi. Some researchers have studied using triazole (propiconazole and - 94 -  tebuconazole) treated solid wood against brown and white-rot fungi. Edlund and Nilsson (1999) have reported that triazoles performed well in laboratory test against both brown and white-rot fungi. Other studies with triazole against white-rot fungi have suggest that they are less effective against white-rot fungi. Schmidt and Gertjejansen (1987) showed that azaconazole at a loading of 2.8 kg/m 3 (PF resin) and 2.5 kg/m 3 (MDI resin) prevented decay by one white-rot fungus and one brown-rot fungus in a laboratory agar-block test. Fang (2004) has reported that incorporating fenpropimorph with 30% K-HDO into OSB provided blocks with complete protection from brown-rot (G.trabeum and P.placenta) and white- rot fungi (T.versicolor and P.ostreatus). 4  Toxic threshold • • •^  • • • ^ • • • ^•  • • • • • • • • MMMMMMMMMMMMMMMM  ZnB (P. Placenta) ZnB (G. trabeum)  0 Low  Middle  High  0.83% ZnB  Target retention level  0 P4 (P.placenta)  —0—PS (G.trabeum)  -  A  -  P4 (G.trabeum)  0 ZnB (P. Placenta)  PS (P.placenta)  ^ ZnB (G. trabeum)  Figure 7.4 Average mass losses of preservative IV and V vs. 0.83% ZnB-brown-rot  The average mass loss of all samples was less than 3%, which is more effective than zinc borate treated against both types of decay fungi except at the 0.085% target loading level of preservative V. At the 0.085% of preservative V, the average mass loss was 2.28% against - 95 -  P.placenta and 1.39% against G. trabeum, and 2.07% against T.versicolor and 1.71% against I. lacteus, which provided equivalent protection to 0.85% zinc borate treated OSB. This suggests  that relatively small amounts of preservative V are needed to provide adequate panel protection against both types of decay fungi.  Toxic thresholds  ZnB (I. lacteus)  2  ZnB (T. versicolor)  1  Low  Middle  High  0.83% ZnB  Target retention level  —.—P4 (7:versicolor)  —X - PS (Idacteus)  ^  ^  P4 (Llacteus)  ^  0 ZnB (7. versicolor)  —0 — PS (T. versicolor)  ^  ZnB (I. lacteus)  Figure 7.5 Average mass losses of preservative IV and V vs. 0.83% ZnB-white-rot  Preservatives containing fenpropimorph as the main active ingredient only performed well against both types of decay fungi when the retention level of fenpropimorph was higher than 0.21% mlm. The samples with a chemical retention level lower than 0.21% had a mass loss higher than 3%. For example, the middle retention level of preservative VI (0.10% of fenpropimorph and 0.012% of organic fungicide) which contains less fenpropimorph, gave a similar weight loss against brown-rot fungi, but a slightly lower mass loss with white-rot fungi compared to the highest application level of preservative III (0.234% of fenpropimorph). - 96 -  Combinations of fungicides that are especially effective are those in which the component fungicides have different and complementary modes of action (Xue 2005). For brown-rot fungi, the average weight loss of preservative III was 1.96% against P. placenta and 1.54% mass loss against G. trabeum, whereas the average mass loss of preservative VI was 1.63% against P. placenta and 1.63% against G. trabeum. For white-rot fungi, the average mass loss of preservative III was 1.80% against T versicolor and 2.47% against I. lacteus, while the mass loss for T. versicolor and I. lacteus was 2.05% and 2.22%. The experimental data indicate that incorporating of cyproconazole with fenpropimorph provided a better protection against whiterot fungi. However, there was no significant difference against brown-rot fungi.  7.3.2 Estimation of biocide toxic threshold retention Based on the results, it is possible to estimate the approximate amount of preservative needed to give control the mass loss at 3% for 12 week exposure using linear or curve linear regression. However, estimating the amount of biocides against decay to be used in real life is not possible from laboratory condition since the real environment condition of OSB in residential use is different. Figure 7.6 to 7.11 show the trend of mass loss vs. the retentions after 12 weeks of exposure. To estimate the toxic threshold retention, the selection was based on the most effective decay fungus for each preservative. The average mass loss of the preservative I was higher against I. lacteus. Therefore, the toxic threshold retention was based on mass losses of treated blocks against I. lacteus (Figure 7.6). Using a linear regression (y= -3.4577x +6.4897 R 2 = 0.8386, x refers to retention level, y refers to weight loss) based on mass loss, the approximate threshold retention to be approximately 1.01%m/m.  - 97 -  7 6  O  y = -3.4577x + 6.4897 R 2= 0.8386  Toxic threshold  O  o 0  ^  ^ 0.5^1 1.5 Target loading level (% m/m)  2  Figure 7.6 Estimation of biocide toxic threshold retention for preservative I  Preservative II also performed the worst against I. lacteus (Figure 7.7). Using a linear regression (y= -13.85x +16.016 R2 = 0.4779, x refers to retention level, y refers to mass loss) based on a 3% mass loss was estimated that approximate threshold retention of 0.94%m/m, could completely prevent fungal decay. 25  20 y = -13.85x + 16.016  e  I  R 2 = 0.4779  15  O  O  10  O O 5  0-  0  0.1^0.2^0.3  Toxic thresholds  ^  0.4  ^  0.5  0.6  Target loading level (% m/m)  Figure 7.7 Estimation of biocide toxic threshold retention for preservative II - 98 -  ^ ^  Preservative III also performed the worst against I. lacteus (Figure 7.8). Using a linear regression (y= -28.426x + 9.1962 R 2 = 0.5043, x refers to retention level, y refers to mass loss) based on mass loss was estimated that approximate retention level of 0.218%m/m, could completely prevent fungal decay. 14 12 10  y = -28.426x + 9.1962 R 2 = 0.5043  8 6  L  8 0^  8  ^4  0 0.05  ^  0.1^0.15  oxic thresholds °  ^  0.2  ^  0.25  Target loading level (% m/m)  Figure 7.8 Estimation of biocide toxic threshold retention for preservative III  Preservative IV performed the worst against G. trabeum (Figure 7.9). Using a curve linear regression (y= 4.4623 x 2 -4.9709 x +2.6074 R 2 = 0.3955, x refers to retention level, y refers to mass loss) based on 3% mass loss was estimated that the toxic threshold retention of approximately 0.0856 %m/m, could completely prevent fungal decay.  • • • • MMMMMMMMM  MMMMMMM  M • • • • • • • MMMMMMMMM • IN • •^..... •  ••  F  Toxic thresholds y = 4.4623x 2 - 4.9709x + 2.6074 R  2  = 0.3955  O  0  ^  0.1^0.2^0.3^0.4^0.5  ^  0.6  ^  0.7  Target loading level (/0m/m)  Figure 7.9 Estimation of biocide toxic threshold retention for preservative IV  Preservative V also performed the worst against P placenta (Figure 7.10). Using a linear regression (y= 20.358 x 2 — 14.927 + 3.4033 R2 = 0.4477, x refers to retention level, y refers to mass loss) based on weight loss was estimated that approximate retention level of 0.029%m/m, could completely prevent fungal decay. 6 5 ,_, 4  ^O  Toxic threshold  o 3  y = 20.358x - 14.927x + 3.4033 R 2 = 0.4477  2  1  0  0.05^0.1^0.15^0.2^0.25^0.3  0.35^0.4  Target loading level (%m/m)  Figure 7.10 Estimation of biocide toxic threshold retention for preservative V - 100 -  Preservative VI also performed the worst against P placenta (Figure 7.11). Using a linear regression (y= -16.6x + 4.2023 R 2 = 0.7201, x refers to retention level, y refers to mass loss) based on weight loss was estimated that approximate retention level of 0.0724%m/m, could completely prevent fungal decay.  6 O  $ 4  O  Toxic threshold y = -16.6x + 4.2023 R 2 = 0.7201 0  0  0.05  0.1^0.15  0.2  0.25  Target loading level (%mlm)  Figure 7.11 Estimation of biocide toxic threshold retention for preservative VI  7.4 Conclusion Weight loss in strandboard produced from the pretreated strands caused by both brown-rot (Gloeophyllum trabeum and Postia placenta) and white-rot (Trametes versicolor and Irpex lacteus) fungi was directly related to chemical retention level, and test species. Both brown-rot and white-rot fungi readily decayed untreated aspen OSB and solid wood. The incorporation of fungicide or a combination of fungicides into strandboard was able to prevent decay in many combinations and retention since mass loss were less than the minimum 3% in this test method. All retention levels of preservative IV and V (mixture of organic fungicide and K-HDO) provided excellent resistance to both brown and white-rot fungi. The maximum mass losses were all recorded at the lowest chemical content and were 1.82% against P. placenta and 1.95% against G. trabeum, and 1.77% against T. versicolor and 1.57% against 1. lacteus. This suggests that only a relatively small amount of this formulation is needed to provide adequate panel protection against both types of decay fungi. Preservatives containing fenpropimorph as the main active ingredient only performed well against both types of decay fungi when the retention level of fenpropimorph was higher than 0.21% m/m. Overall, the enhanced decay resistance from high to low showed the following trend: against both brown and white-rot fungi: preservative IV and V (a mixture of organic fungicide and KHDO) > zinc borate > preservative I (boric acid) > preservative VI (a mixture of organic fungicide and fenpropimorph) > preservative III (fenpropimorph) > preservative II (a mixture of fenpropimorph and K-KHO) >> untreated strandboard > untreated solid wood. Based on mass loss, the following amount of preservatives for each preservative could completely prevent fungal decay: the approximate retention level of 1.01 %m/m for preservative I, 0.94 %m/m for preservative II, 0.218 %mlm for preservative HI, 0.0856 %m/m for preservative IV, 0.029 °Arnim for preservative V, and 0.0724 %mlm for preservative VI. - 102 -  Chapter 8 Summary and conclusions This study was divided into two parts. In the first part, the effective of individual fungicides or combination of fungicides on mold resistance properties of OSB was examined. The second part of study examined the effectiveness of individual fungicides or combination of fungicides on decay resistance and strength properties of OSB. To complete the second part of study, several experiments were done. An initial screening study examined the effect of fungicides or combination of fungicides using an agar-block test to estimate the preservative toxic threshold retention. In addition, the effect of the fungicides on the resin gelation time and viscosity was examined prior to making the test panels. Following this screening phrase, a investigation of the mechanical properties and decay resistance properties of OSB was performed, in which the MOE, MOR, and 1B of replicate samples was recorded, as well as the durability against white-rot and brown-rot fungi using a standard soil-block method. Based on the results from this study, the following conclusions can be derived.  Mold resistance properties  The mold resistance of the OSB was directly correlated to the concentration of each preservative. Greater protection of the OSB was achieved with an increase in preservative retention levels. Based on this experiment, preservatives, which contained propiconazole and/or fenpropimorph with boric acid and a combination of DDAC and IPBC, effectively prevented the mold growth. For example, NP-2 a commercial anti-mold treatment at a retention 1.505 g/m 2 , and LP 15895 at a retention 0.225 g/m 2 and 0.450 g/m 2 and LP 15896 at a retention 1.710 g/m 2 , moldicides from Dr. Wolman GmbH, prevented mold growth effectively (ratings of 1.417 and 1.833 respectively) after the 6 weeks exposure. However, during the study it was noted that - 103 -  factors, such as the physical structure of OSB surface such as species of wood (e.g. maple), and void distribution can influenced the assessment of mold growth.  Estimation preservative toxic threshold retention using agar block test for decay resistance -  In general organic biocides (fungicides) are much more expensive than heavy metalcontaining preservatives. Therefore, determining the preservative toxic threshold retention accordingly is important. In addition, due to the limited action of many organic biocides, the use of combination of organic biocides has potential for increasing efficacy and reducing the cost. From the agar-block test, the decay resistance of the treated wood blocks was directly can related to preservative retention. However, when the fungicides were combined with other selected fungicides in a second screening test, the results were more complex. In general, combinations of fungicides showed better performance against decay fungi than a single fungicide. In some cases, different ratio of two fungicides produced similar mass losses. Combinations of fungicides with different modes of action for controlling fungi may provide broader spectrum protection because of possible complementary protection or synergism between preservatives. Based on the results of the screening phase, and addition input from research at Dr. Wolman GmbH, some biocides from the screening study were then combined, while a few additional biocides were added to the research project.  The influence of preservative on gelation time and viscosity of phenol resin Changes in the viscosity and gelation time are problematic for the operation of an OSB plant. Viscosity changes could significantly affect the flow properties of the resin on the wood furnish and its atomization as it is sprayed onto the wood furnish. In addition, it may require modification to the equipment that supplies the resin to the spray nozzle. Changes in the gelation - 104 -  time may require changes in the press time at OSB plants. Wood preservative were considered compatible with the resin if they did not change their gelation time by ± 2 minutes and the viscosity by ± 35 cPs. For most of the preservatives, changes in the viscosity and gelation time was directly related to retention level. As the fungicide loading level increased, the viscosity and gelation time also increased. As expected, the lowest application level performed better than higher application level. However, most of preservative concentrations were not compatible with PF resin since their addition did cause significant change in the viscosity or the gelation time. An exception was when lowest concentration of preservative V (a mixture of 0.013% organic fungicide and 0.072% K-HDO) which showed good compatibility with PF resin. At 0.085% concentration, the gelation time was increased by 3.8%, the viscosity decreased by 2.9%. The increased gelation time and reduced viscosity was partially offset by using organic fungicide and/or K-HDO in combination with fenpropimorph. Unsatisfactory results from the viscosity and gelation time test, manufacturing strandboard was approached with separate incorporated of preservatives and PF resin during the manufacturing process because of the negative impact of wood preservatives.  The effects of preservatives on mechanical properties According to a one-way ANOVA, there was a distinct difference (at the 5.0% significant level) for bending properties of OSB samples recovered from the outer and inner parts of panel. The reason for the difference in the bending properties for specimens from the outer and inner parts of panels was the alignment of the strands. When the panels were randomly formed by hand, strands were formed parallel to the edge of forming box to prevent the blowing or blistering during the hot pressing. There was no indication that panels prepared from strands pretreated with fungicides or combination of fungicides were weaker than untreated panels in terms of bending and stiffness - 105 -  (P=0.05). However, panels prepared from strands pretreated at the highest retention levels of preservatives containing 30% K-HDO as an active ingredient, had a significant reduction in MOR and MOE compare to untreated strandboard. For example, preservative V, which incorporated K-HDO, caused a maximum 23.6% reduction in MOR and 30.5% reduction in MOE. The solution of preservative had a relatively high in pH, which could change the pH of the wood surface and interfere and modify the resin cure during hot pressing. The addition of all biocides generally showed a slight negative effect on the panel internal bonding strength compared to the untreated controls. The size of reduction in the IB varied with type of preservative and retention. The greatest reduction occurred at the 0.635% application level of preservative IV, which contains 8% organic fungicide and 30% K-HDO the as active ingredients. The incorporation this preservative caused a maximum 43.17% reduction in 1B strength. The reason for the big reduction of IB strength was most likely the deposition of preservative residue on the strand surface which would reduce the bonding efficiency of the adhesive.  Decay resistance preservative modified strandboard Weight loss in OSB prepared from pretreated strands treated was directly correlated to the chemical retention and the fungal type. Decay by both brown and white-rot fungi was observed for untreated aspen strandboard and untreated solid pine or poplar blocks. The mass losses of the untreated OSB were slightly lower than those of the untreated solid wood. This may be related to residual of phenol formaldehyde. The influence of wax on the MC can be unhelpful since the MC of the OSB is similar to that of the solid wood. The incorporation of many preservative formulations into OSB provided a suitable protection, since mass losses from the soil-block test were well below the minimum 3% mass loss, required by the standard soil-block method. Trends of increasing protection were observed with higher - 106 -  retention level of preservatives. The experimental results indicated that combining organic fungicide with fenpropimorph provided a better protection against white-rot fungi compared to single preservative contain fenpropimorph. However, there was no significant improvement against brown-rot fungi. For example, the median retention of preservative VI (0.10% of fenpropimorph and 0.012% of organic fungicide) which contains less fenpropimorph, gave a similar weight loss against brownrot fungi and a slightly lower mass loss was observed against white-rot fungi compared to the highest application level of preservative III (0.234% of fenpropimorph). The addition of organic fungicide and K-HDO in strandboard was the most effective combination against and both brown and white-rot fungi. These results proved that combination of two or more fungicides gave a greater protection against microorganism than can be achieved with only one of the fungicides. Overall, the decay resistance results suggest the following trend: against both brown and white-rot fungi: preservative IV and V (a mixture of organic fungicide and K-HDO) zinc borate > preservative I (boric acid) > preservative VI (a mixture of organic fungicide and fenpropimorph) > Preservative III (fenpropimorph) > preservative II (a mixture of fenpropimorph and K-KHO) >> untreated strandboard > untreated solid wood. Based on mass loss, the following amount of preservatives for each preservative could completely prevent fungal decay: the approximate retention level of 1.01 %mlm for Preservative I, 0.94 %mlm for preservative II, 0.218 %mlm for preservative III, 0.0856 %m/m for preservative IV, 0.029 %m/m for preservative V, and 0.0724 %mlm for preservative VI. This information developed from this study will enable more durable OSB to be developed using formulation of organic biocides.  - 107 -  Chapter 9 Recommendations 1. For mold resistance study, it was difficult to macroscopically rate OSB samples because of color variations in the product. Evaluation of mold growth should be studied further to provide more accurate measurements. 2. The effective preservatives from mold resistance study should be studied with a larger size of sample. 3. The addition of preservatives strands prior to board production showed a negative effect on the internal bonding strength. These organic preservatives should be studied with other type of resin. 4. The addition of preservative IV and V, which contain organic fungicide and K-HDO, provided a great protection against both brown and white-rot fungi even at the lowest retention level. Therefore, another evaluation of decay resistance should be studied with lower retention level of preservative IV and V. 5. The addition of propiconazole which provided a great protection against mold fungi, and organic fungicide which provided a great protection against decay fungi. 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F. Shupe. 2004. "An Exploratory Study of Home Builder, New-Home Home Owner and Real Estate Agent Perceptions and Attitudes about Mold." For Prod J. 54(12):289-295 Winandy, J.E. and B.H.River. 1986. Evaluation of a method for testing adhesive- preservative compatibility. For Prod J. 6(1):27-32 Wu, Q. 2004. Preservative treated structural wood composites for durable home constructions. Presented at the NSF and HUD Housing Research Workshop, Orlando, FL. February 13, 2004.  - 115 -  Xue, Z., 2005. Wood preservatives and methods of wood preservation. The Patent Cooperation Treaty. WO 2005/099982 A1. Access date: November 2007. http://www.wipo.int/patentscopedb/en/wads.jsp?IA=US2005011402&LANGUAGE=EN&ID=id 00000002188248&VOL=49&DOC=0029ac&WO=05/099982&WEEK=43/2005&TYPE=Al& DOC_TYPE=PAMPH&PAGE=1  Appendix A "Raw data" Appendix Al LP 15850 mold growth and rating  Sample  Act Ball Bd2 Bfl Cf8 Dc4 All Ba4 Bc1  Cc3 Day Df5 Aa6 Aft Bel Cd8 Db4 Ddl  Mold growth (%), Rating (PT)  Uptake (g/m 2 )  1 week  2 week  1.955 2.034 1.952 2.049 1.991 1.874 2.198 1.935 1.962 2.102 2.062 1.971 3.850 4.254 4.107 4.181 4.129 3.969 4.024 3.996 3.953 4.072 4.348 3.983 8.030 8.210 8.125 8.375 7.941 8.376 7.965 8.285 8.226 8.100 8.614 7.560  0 1 1 3 0 1 0 0 0 0 1 2 0 0 0 0 0 0 0 1 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 2 2 5 1 1 1 0 1 0 3 4 0 0 0 0 0 0 0 3 1 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 1 1 1 0 1 0 0 0 0 1 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0  ,  0 1 1 2 1 1 1 0 1 0 1 1 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0  3 week  4 week  15 15 30 25 15 10 3 5 15 10 25 30 15 10 15 15 7 5 4 10 8 25 5 1 15 4 1 5 15 5 2 1 1 1 1 4  30 25 40 30 20 15 5 7 20 15 30 30 25 15 20 20 15 10 7 15 13 30 7 5 20 10 5 10 20 10 10 5 3 3 3 5  2 2 3 3 2 2 2 2 2 2 2 3 2 2 2 2 2 2 1 2 2 2 2 1 2 1 1 2 2 2 1 1 1 1 1 1  2 2 3 3 3 2 2 2 2 2 3 3 2 2 2 2 2 2 2 2 2 3 2 2 2 1 2 1 2 2 1 2 1 1 1 2  5 week  65 60 65 55 45 50 35 50 40 35 55 60 45 25 25 20 20 15 15 35 35 35 20 25 25 25 10 20 30 15 15 10 5 10 5 15  3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 3 3 3 2 2 2 2 2 2 3 2 2 2 2 2 2 2  6 week  75 4 3 65 70 4 3 65 3 65 75 4 65 3 70 4 3 60 3 55 4 75 75 4 3 65 3 50 45 3 50 3 40 3 40 3 35 3 60 3 55 3 60 3 40 3 35 3 45 3 35 3 25 2 35 3 50 3 30 3 30 3 20 2 10 2 20 2 10 2 30 3  Appendix A2 LP 15896 mold growth and rating  Sample Ac8 Bell  ca Db7 Dcl 1 Dell Ac6 Ad11 Bd9 Cab  Ce8 Dcl Act Af3 Bc3 Ca10 Cd6 Cf9  Mold growth (%), Rating (PT)  Uptake (g/m 2 )  2.513 2.463 2.258 2.700 2.639 2.636 2.400 2.674 2.654 2.676 2.497 2.725 5.300 4.989 5.242 4.931 4.940 5.316 5.042 5.283 4.928 5.482 4.944 5.015 11.252 8.803 10.374 9.978 10.219 11.047 10.187 9.987 10.112 10.755 10.256 10.726  1 week  2 week  3 week  4 week  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0  1 1 2 0 3 3 8 4 0 3 2 0 1 0 0 0 1 10 0 0 0 0 4 4 0 0 0 0 3 1 0 0 1 0 0 0  2 3 5 1 5 5 15 7 0 5 4 0 3 0 0 0 3 15 0 0 4 4 8 8 0 0 0 0 5 3 0 0 2 1 1 1  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0  1 1 1 0 1 1 2 1 0 1 1 0 1 0 0 0 1 2 0 0 0 0 1 1 0 0 0 0 1 1 0 0 1 0 0 0  1 1 2 1 2 2 2 2 0 2 1 0 1 0 0 0 1 2 0 0 1 1 2 1 0 0 0 0 2 1 0 0 1 1 1 1  -  5 week  4 5 10 5 10 15 30 15 5 7 15 5 7 5 3 0 10 20 3 5 10 5 15 10 2 3 1 0 7 5 3 1 4 2 2 5  1 2 2 2 2 2 3 2 2 2 2 2 2 2 1 0 2 2 1 2 2 2 2 2 1 1 1 0 2 2 1 1 1 1 1 2  6 week  10 10 15 15 30 25 50 30 10 15 25 10 10 10 5 5 15 25 5 10 15 10 25 20 4 4 4 1 10 7 5 4 5 5 5 10  2 2 2 2 3 2 3 3 2 2 2 2 2 2 1 1 2 2 2 2 2 2 2 2 1 1 1 1 2 2 2 1 2 2 2 2  Appendix A3 LP 15895 mold growth and rating  Sample  Aa2 Ad6 Bc11 Cc8 Dag Db8 Aa7 Af5 Ca5 Cb11 Cd2 Ddb Aa1 Bb10 Bf4 Ccl Db1 0 Df11  Mold growth (%), Rating (PT)  Uptake (g/m 2 )  2.458 2.490 2.659 2.599 2.799 2.516 2.425 2.518 2.470 2.437 2.749 2.499 4.836 5.262 5.542 4.872 4.870 4.998 4.910 5.531 4.971 4.892 5.191 4.949 9.871 10.843 11.160 9.574 10.314 10.969 9.604 10.616 10.210 10.310 11.036 10.124  1 week  2 week  3 week  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  1 1 4 3 1 8 6 5 4 2 1 2 0 8 3 2 0 0 0 0 7 1 1 1 0 0 0 0 3 0 0 0 0 0 0 3  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  1 1 1 1 1 2 2 2 1 1 1 1 0 1 1 1 0 0 0 0 2 1 1 1 0 0 0 0 1 0 0 0 0 0 0 1  4 week  3 5 15 5 5 10 10 10 6 2 1 2 0 8 4 0 0 1 3 1 10 4 5 1 0 0 0 0 5 0 0 0 0 1 5 5  1 2 2 2 2 2 2 2 2 1 1 1 0 2 1 0 0 1 1 1 2 1 2 1 0 0 0 0 2 0 0 0 0 1 2 2  ,  5 week  6 week  5 7 45 15 10 15 15 15 6 3 2 3 0 15 4 0 0 4 5 2 10 10 7 2 2 0 0 0 4 0 0 0 3 2 7 5  15 15 50 20 30 25 20 20 7 4 4 4 1 20 4 1 1 5 10 5 15 15 10 4 5 3 1 1 7 1 1 1 5 4 10 7  2 2 3 2 2 2 2 2 2 1 1 1 0 2 1 0 0 1 2 1 2 2 2 1 1 0 0 0 1 0 0 0 1 1 2 2  2 2 3 2 3 2 2 2 2 1 1 1 1 2 1 1 1 2 2 2 2 2 2 1 2 1 1 1 2 1 1 1 2 1 2 2  Appendix A4 NP-2 mold growth and rating  Sample Ab10 Bg4  Cc11 Dal Dd4 Deb Af4 Ag3 Bc9 Dd11 Df4 Dg9  Ac7 Af7 Bf3 Cb1 Cf7 Del  Mold growth (%), Rating (PT)  Uptake (g/m 2 )  0.523 0.503 0.506 0.514 0.504 0.498 0.506 0.511 0.511 0.503 0.504 0.520 0.989 0.992 0.995 0.999 1.008 1.030 1.001 1.018 1.015 1.029 1.023 1.042 1.973 1.987 2.041 1.982 2.017 2.043 2.038 2.112 2.047 2.116 1.977 2.022  1 week  2 week  3 week  4 week  0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 4 0 2 1 0 3 2 0 0 1 1 2 0 0 0 2 0 0 3 0 0 0 0 0 1 0 0 0 0 0 0  0 3 4 0 3 7 6 15 8 5 8 5 3 0 2 1 4 8 4 1 3 3 4 5 4 2 0 3 1 2 0 0 2 3 0 2  3 7 3 2 10 10 15 20 15 10 10 8 3 1 3 2 5 10 5 1 3 5 5 5 4 3 1 5 1 5 0 0 3 5 3 3  0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 1 0 1 1 0 1 1 0 0 1 1 1 0 0 0 1 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0  0 1 1 0 1 2 2 2 2 2 2 2 1 0 1 1 1 1 1 1 1 1 1 2 1 1 0 1 1 1 0 0 1 1 0 1  1 2 1 1 2 2 2 2 2 2 2 2 1 1 1 1 2 2 1 1 1 2 2 2 1 1 1 2 1 2 0 0 1 2 1 1  5 week  4 7 5 3 20 25 30 35 30 20 20 20 5 3 13 10 7 10 7 7 7 10 15 10 5 3 2 7 1 7 1 1 4 10 5 3  1 2 2 1 2 2 2 2 2 2 2 2 2 1 2 2 2 2 2 2 2 2 2 2 2 1 1 2 1 2 1 1 1 2 2 1  6 week  7 10 5 5 25 30 35 45 35 25 35 35 7 5 15 15 10 15 10 10 15 15 20 15 7 5 5 10 3 10 1 1 5 15 7 3  2 2 2 2 2 3 3 3 3 2 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 2 1 1 2 2 2  Appendix B Appendix B1 One-way analysis of mold coverage (%) by treatment  Oneway Analysis of Mold Coverage (%) By Treatment 110 ^ 100 90 80 -  O O  7060 5040 30 20 100^ Control-1 Control-3^LP 15850-4^LP 15895-10 LP15895-5^_P15896-2.5 'P2-0.5 NP2-2 Control-2 LP15850-2^_P15850-8^_P15895-2.5 LP15896-10 LP15896-5 ^NP2-1 Treatment  Oneway Anova Summary of Fit Rsquare Adj Rsquare Root Mean Square Error Mean of Response Observations (or Sum Wgts)  0.951426 0.997305 8.171582 36.47778 180  Analysis of Variance Source Treatment Error C. Total  OF Sum of Squares Mean Square ^F Ratio Prob > F 14^215809.08^15414.9 230.8498^<.0001 165^11017.83^66,8 179^226826.91  Means for Oneway Anova Level Control-1 Control-2 Control-3 LP 15850-2 LP15850-4 LP15850-8 LP15895-10 LP15895-2.5 LP15895-5 LP15896-10 LP15896-2.5 LP15896-5 NP2-0.5 NP2-1 NP2-2  Number  Mean  Std Error  Lower 95%  Upper 95%  12 12 12 12 12 12 12 12 12 12 12 12 12 12 12  95.8333 97.9167 98.3333 67.9167 47.9167 28.3333 3.8333 17.8333 7,5833 5.3333 20.4167 12.9167 24.3333 12.6667 6.0000  2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589 2.3589  91.176 93.259 93.676 63.259 43.259 23.676 -0.824 13.176 2.926 0.676 15.759 8.259 19 .676 8.009 1.342  100.49 102.57 102.99 72.57 52.57 32.99 8.49 22.49 12.24 9.99 25.07 17.57 28.99 17.32 10.66  Std Error uses a pooled estimate of error variance  Al Pairs Ti.key-Kramer 0.05  Appendix B2 One-way analysis of mold coverage (%) by treatment (continued)  Oneway Analysis of Mold Coverage (Oh) By Treatment  1 Means Comparisons Dif=Mean[i]-Mean[j]  Control-3 Control-2 Control-1 L 0 15850-2 LP15850-4 LP15850-8 NP2-0.5 LPI5896-2.5 LPI5895-2.5 LP15896-5 ^NP2-1 LP15895-5^NP2-2 LP15896-I0 LP15895-10 Control-3^0.0000^0.4167^2.5000^30.4167^50.4167 70.0000 74.0000^77.9167^80.5000^85.4167 85.6667^90.7500 92.3333^93.0000^94.5000 Control-2^-0.4167^0.0000^2.0833^30.0000^50.0000^69.5833 73.5833^77.5000^80.0833^85.0000 85.2500^90.3333 91.9167^92.5833^94.0833 Control-1^-2.5000^-2.0833^0.0000^27.9167^47.9167 67.5000 71.5000^75.4167^78.0000^82.9167 83.1667^88.2500 89.8333^90.5000^92.0000 LF15850-2^-30.4167 -30.0000 -27.9167 ^0.0000^20.0000^39.5833 43.5833^47.5000^50.0833^55.0000 55.2500 60.3333 61.9167^62.5833^64.0833 LP15850-4^-50.4167 -50.0000 -47.9167 -20.0000^0.0000^19.5833 23.5833^27.5000^30.0833^35.0000 35.2500 40.3333 41.9167 ^42.5833^44.0833 LP15850-8^-70.0000 -69.5833 -67.5000 -39.5833 -19.5833^0.0000^4.0000^7.9167^10.5000^15.4167 15.6667^20.7500 22.3333^23.0000^24.5000 NP2-0.5^-74.0000 -73.5833 -71.5000 -43.5833 -23.5833^-4.0000^0,0000^3.9167^6.5000^11.4167 11.6667^16.7500 18.3333^19.0000^20.5000  LP15896-2.5 -77.9167 -77.5000 -75.4167 -47.5000 -27.5000^-7.9167^-3.9167^0.0000^2.5833^7.5000^7.7500^12.8333 14.4167^15.0833^16.5833 LP15895-2.5 -80.5000 -80.0833 -78.0000 -50.0833 -30.0833 -10.5000^-6.5000^-2.5833^0.0000^4.9167^5.1667^10.2500 11.8333^12.5000^14.0000 LP15896-5^-85. 4 167 -85.0000 -82.9167 -55.0000 -35.0000 -15.4167 -11.4167^-7.5000^-4.9157^0.0000^0.2500^5.3333^6.9167^7.5833^9.0833 NP2-1^-85.6667 -85.2500 -83.1667 -55.2500 -35.2500 -15.6667 -11.6667 ^-7.7500^-5.1667^-0.2500^0.0000^5.0833^6.6667^7.3333^ 8.8333 LP15895-5^-90.7500 -90.3333 -88.2500 -60.3333 -40.3333 -20.7500 -16.7500 ^-12.8333^-10.2500^-5.3333^-5.0833^0.0000^1.5833^2.2500^ 3.7500 9P2-2^-92.3333 -91.9167 -89.8333 -61.9167 -41.9167 -22.3333 -18.3333 ^-14.4167^-11.8333^-6.9167^-6.6667^-1.5833^0.0000^0.6667^ 2.1667 LP15896-10^-93.0000 -92.5833 -90.5000 -62.5833 -42.5833 -23.0000 -19.0000 ^-15.0833^-12.5000^-7.5833^-7.3333^-2.2500 -0.6667^0.0000^ 1.5000 LP15895-10^-94.5000 -94.0833 -92.0000 -64.0833 -44.0833 -24.5000 -20.5000^-16.5833^-14.0000^-9.0833 -8.8333^-3.7500 -2.1667^-1.5000^0.0000 Alpha. 0.05 Comparisons for all pairs using Tukey-Kramer 115D q' 3.44360 Abs(Dif)-L5D Control-3 Control-2 Control-1 015850-2 1915850-4 LP15850-8 NP2-0.5 LP15896-2.5 1915895-2.5 LP15896-5 ^NP2-1 LP15895-5^NP2-2 LP15896-10 1915895-10 Control-3^-11.4880 -11.0713 -8.9880^18.9287^38.9287^58.5120 62.5120^66.4287^69.0120^73.9287 74.1767^79.2620 80.8454^81.5120^83.0120 Control-2^-11.0713 -11.4880 -9.4046^18.5120^38.5120^58.0954 62.0954^66.0120^68.5954^73.5120 73.7620^78.8454 80.4287^81.0954^82.5954 Control-1^-8.9880^-9.4046 -11.4880^16,4287^36.4287^56.0120 60.0120^63.9287^66.5120^71.4287 71.6787 76,7620 78.3454^79.0120^80,5120 LP15850-2^18.9287 18.5120 16.4287 -11.4880^8.5120^28.0954 32.0954^36.0120^38.5954 43.5120 43.7620^48.8454 50.4287^51.0954^52.5954 1115850-4^38.9287 38.5120 36.4287^8.5120 -11.4880^8.0954 12.0954^16.0120^18.5954^23.5120 23.7620^28.8454 30.4287^31.0954^32.5954 LP15850-8^58.5120 58.0954 56.0120^28.0954^8.0954 -11.4880 -7.4880^-3.5713^-0.9880^3.9287^4.1787^9.2620 10.8454^11.5120^13.0120 NP2-0.5^62.5120 62,0954 60.0120^32.0954^12.0954^-7.4880 -11.4880^-7.5713^-4.9880^-0.0713^0.1787^5.2620^6.8454^7.5120^9.0120 1915896-2.5^66.4287 66.0120 63.9287^36.0120^16.0120 -3.5713^-7.5713^-11.4880^-8.9046^-3.9880 -3.7380^1,3454^2.9287^3.5954^5.0954 LP15895-2.5^69.0120 68.5954 66.5120^38.5954^18.5954^-0.9880 -4.9880^-8.9046^-11.4880 ^-6.5713^-6.3213^-1.2380^0.3454 ^1.0120^2.5120 LP15896-5^73.9287 73.5120 71.4287^43.5120^23.5120^3.9287 -0.0713^-3.9880^-6.5713 -11.4880 -11.2380^-6.1546 -4.5713^-3.9046^-2.4046 NP2-1^74.1787 73.7620 71.6787^43.7620^23.7620^4.1787^0.1787^-3.7380^-6.3213 -11.2380 -11.4880^-6.4046 -4.8213^-4.1546^-2.6546 LP15895-5^79.2620 78.8454 76.7620 48.8454 ^28.8454^9.2620^5.2620^1.3454^-1.2380^-6.1546 -6.4046 -11.4880 -9.9046 ^-9.2380^-7.7380 NP2-2^80.8454 80.4287 78.3454^50.4287^30.4287^10.8454^6.8454^2.9287^0.3454^-4.5713 -4.8213^-9.9046 -11.4880^-10.8213^-9.3213 LP15896-10^81.5120 81.0954 79.0120^51.0954^31.0954^11.5120^7.5120^3.5954^1.0120^-3.9046 -4.1546^-9.2380 -10.8213^-11.4880^-9.9680 LP15895-10^83.0120 82.5954 80.5120^52.5954^32.5954^13.0120^9.0120^5.0954^2.5120^-2.4046 -2,6546^-7.7380 -9.3213^-9.9880^-11.4880 Positive values show pairs of means that are significantly different.  - 122 -  Appendix C Appendix Cl The conversion of the loading levels  Preservative type  I  II  III  IV  V  VI  Trade name  Loading level (%m/m)  Resin  ug wood  content  preservative  (%m/m)  / mg resin  LP15853  0.44  5  88  LP15853  0.88  5  176  LP15853  1.76  5  352  LP16202  0.13  5  26  LP16202  0.26  5  52  LP16202  0.51  5  102  LP16203  0.063  5  12.6  LP16203  0.117  5  23.4  LP16203  0.234  5  46.8  LP 15849 : LP 15843  0.013 : 0.14  5  30.6  LP 15849 : LP 15843  0.027 : 0.29  5  63.4  LP 15849 : LP 15843  0.055 : 0.58  5  127  LP 15849 : LP 15843  0.013 : 0.072  5  17  LP 15849 : LP 15843  0.027: 0.140  5  33.4  LP 15849 : LP 15843  0.055 : 0.290  5  69  LP 16203 : LP 15849  0.05 : 0.006  5  22.4  LP 16203 : LP 15849  0.10 : 0.012  5  47  LP 16203 : LP 15849  0.21 : 0.025  5  94  Appendix D "One-way analysis of static bending properties" Appendix DI Preservative I-outer  1  Oneway Analysis of MOR (MPa) By Pattern  Oneway Analysis of MOE (GPa) By Pattern  45  8.5  40  35 0  30  5.5  CONTROL  F1-1  F1-2 Pattern  I Oneway Arrow,  F1-3  All Pairs Tukeyararner 0.05  CONTROL  F1.1  I -2  FI-3  Pattern  All Pairs Tukey-Kramer 085  Oneway Anova  I Summary of Fit  I Summary of Fit Rsquare^ 0.3628 Adj Rsquare^0.2035 Root Mean Square Error^4.713924 Mean of Response^33.93438 Observations (or Sum Wats)^16  Rsquare^0.541968 Adj Rsquare^043121 Root Mean Square Enor ^0.583674 Mean of Response^7.22 Observations (or Sum mos)^16  Analysis of Variance  Analysis of Variance Source Pattern Error C. Total  25  OF Sum of Square, Mean Squart 3^4.8961000^1.63203 12^40881000^0.34068 15^8.9842000  Source Pattern Ewor  F Ratic Nob F 4.7906^0.0203  C. Total  DF Sum of Squares Mean Square 3^151.82287^50.6076 12^266.65293^22.2211 15^418.47579  F Ratio Probe F 2.2775^0.1318  I Means for Oneway Anova  I Means for Oneway Anova  Level^Numbe^Mean Std Error Lower 95% Upper 95% CONTROL^4 37,0975 2.3570^31.962^42.233 F.1-^4^35,0925 2.3570^29.957^40.228 F1-2^4^34.7125 13570^29.577^39.848 F1-3^4^28,8350 2.3570^23.700^33.970 Sod Error uses a pooled estimate of error variance  Level^Numbe Mean Std Eno Lower 95% Upper 95% CONTROL^4 8.13750 0,29184^7.5016^8.7734 Fl-I.^4 7,09750 0.29154^6.4616^7.7334 11 , 2^4 6.98250 0,29184^6.3466^7.6184 F1-3^4 6.66250 029184^6.0266^7.2984 Srri Frrnr !AM a neeleel A-termer of error  Preservative I-inner Oneway Analysis of MOE (GPa) By Pattern  Oneway Analysis of MOR (MPa) By Pattern 32.5 30- 27.5 a 25m 225-, 20175  1  Oneway Anova  I Summary of Fit  a n Squarr^F Rapt Prob F  0.252483^0 6110^0.6207 0.413229  I Means for Oneway Anova level Numbe Mean SW Erro Lower 95% Upper 95% 4.7697 CONTROL 4 5.47000 0.32141 6.1703 5.7328 4 3322 F1-1 4 5.03250 0. 32141 4 5.34000 032141 F1-2 4.6397 6.0403 4.2372 5.6379 F1-3 4 4.9375D 0.32141 Strl Fnre  noes a  r  0.05  1  Summary of Fit  I Analysis of Variance  I Analysis of Variance  OF Sum of Squares 3^0.7574500 12^4.9587500 15^5.7162000  I ()newsy Anova  Pattern  Rsquare^0.132793 Adj [square^-0.08401 Root Mean Square Error^4.143452 Mean of Response^25.0625 Observations (at Sum W8ts)^16  Rsquare^0.132509 Adj Rsquare^-0.06436 Root Mean Square Error^0.642829 Mean of Response^5.195 Observations (or Sum Wits)^16  Source Pattern Error C. Total  -2^F1-3^PP Pai  CONTROL^F1  nnnled omenare of owe ...nee  Source Pattern Error C. Total  Df Sum of Squares Mean Square 3^31.54715^10.5157 12^206.01835^17,1682 15^237,56550  F Ratic Prob F 0.6125^0.6198  I Means for Oneway Anova  Level^Numbe^Mean Std Eno , Lower 95% Upper 95% CONTROL^4^23.7725 2.0717^19.259^28.286 F l - 1^4^23.5550 20717^19.041^28.069 F1-2^4^26.3250^2.0717^21.811^30.839 F1-3^4^26.5975^2.0717^22.084^31,111 SW Error uses a pooled estimate of error variance  - 124 -  Appendix D2 Preservative 11-outer )newsy Analysis of MOR (MPa) By Pattern  Oneway Analysis of MOE (GPa) By Pattern  45  6.5 -  2,'1 . 7.5 to  -  rc 7-  o ° 30-  6.5 -  25-  6  All Pairs  F2-3  CONTROL^F2-I^F2.2  F2.1  CONTROL  F2-2  0.05  Pattern  All Pairs  F2-3  Tukev-Kramer 0.05  Pattern  1 Oneway Anova  ( Oneway Anova  1 Summary of Fit  Summary of Fit  Rsquare  Ad( Rsquare  Root Mean Square Error  0.457135 0.321419  Rsquare  0.560383  Root Mean Square Error  Mean of Response  0.264665  Rsquare  7.37  Observations (or Sum Wgts)  0.080831 4.829487  Mean of Response  16  33.8425  Observations (or Sum Wgts)  Analysis of Variance  16  (Analysis of Variance  Source  OF Sum of Squares Mean Square  F Ratio Prob > F  Source  OF Sum of Squares  Mean Square  F Ratio Prato > F  Pattern  3^3.1732500^1 05775  3,3683^0.0548  Pattern  3^100.73835  33.5794  1.4397^0.2800  12^279.89735 15^380.62570  23 3239  Error  12^3,7663500^0.31403  C. Total  15^6.9416000  Error  C. Total  I Means for Oneway Anova  1 Means for Oneway Anova  Number  Mean  Std Error  Lower 95%  Upper 95%  CONTROL  4  8.13750  0.28019  7.5270  8.7480  CONTROL  F2-1  4 4  7,18500  0.28019  6.5745  7.7955  7.06500  6.4545  7.6755  4  7.09250  0.28019 028019  F2-1 F2.2  6.4620  7.7030  F2-2 F2-3  ^4  20  Tukey-Krarner  Std Error uses a pooled estimate of error variance  Number^Mean  Level  Std Error Lower 95% Upper 95% 42.359  4^37.0975^24147^31.836 4^35.0950^2.4147^29.834  40.356 38,046  4^32.7850^2.4147^27.524 ^30,3925^2,4147^25.131  F2-3 Std Error u  35.654  a pooled estimate of error variance  Preservative II-inner Oneway Analysis of MOR (MPa) By Pattern  Oneway Analysis of MOE (GPa) By Pattern  30 27.5  6.5 6--  - 25  5,5-i  22.5  C  0 4,5 -  CONTROL  F2-1  F2.2  All Pairs Tukey-Kramer  F2-3  15 CONTROL^F2-I^F2-2  0.05  Pattern  Pattern  F2-3  i Pairs Tukey-Kramer 0.05  Oneway Anova  Oneway Anova  Summary of Fit  Summary of Fit Rsquare  0.168225  Rsquare^  Ad( Rsquare  -0.03972  84 Rsquare^0.067312  0,81535  Root Mean Square Error^3.795921  5.29  Mean of Response^23138563  Root Mean Square Error Mean of Response Observations (or Sum Wgts)  0.25385  Observations (or Sum Wgts)^16  16  Analysis of Variance  Analysis of Variance Source  OF Sum of Squares Mean Square  F Ratio Prob > F  Source  DF Sum of Squares Mean Square  F Ratio Nob > F  Pattern  3^1.6134500^0.537817  0.8090^0.5129  Pattern Error  3^58.82557^19.6085  1,3609^0.3016  12^172,90622^14.4690  C. Total  15^231.73379  Error C. Total  12^7.9775500^0.664796 15^9.5910000  Means for Oneway Anova  Means for Oneway Anova Number  Mean  Std Error  Lower 95%  Upper 95%  Level^Number  Mean  Std Error Lower 95% Upper 95%  CONTROL  4  5.47000  0.40768  4.5818  6.3582  CONTROL^4  23.7725  1.8980^19.637^27.908  F2-1 F2-2  4 4  5.97750  0.40768  45893  4.74000  0.407E8  3.8518  6.3657 5.6282  F2.1^4 F2-2^4  23.5200 21.4375  F2.3  4  5.47250  0.40768  4.5843  6.3607  F2-3^4  26.8125  1.8980^19.385^27.655 1.8980^17.302^25.573 1,8980^22.677^30.948  Level  Std Error uses a Pooled estimate of error variance  Std Error uses a pooled estimate of error variance  - 125 -  Appendix D3 Preservative III-outer Oneway Analysis of MOR (MPa) By Pattern  Oneway Analysis of MOE (GPa) By Pattern  w 13  8.5  45  8  40 35  75-  cc 0 10  0  25  6.56 CONTROL^F3-i^F3-2^F3.3 Pattern  I  20  All Pairs Tukty-Kramer 0.05  All Pairs Tukey-Kramer 0.05  F3-3  Summary of Fit Rsquare^0.536542 4:1) Rsquare^0.420678 Root Mean Square Error ^5.404979 Mean of Response ^31.67938 Observations (or Sum Wgts)^16  Rsquare^0.449548 Adj Rsquare^0.310685 Root Mean Square Error^0.696692 Mean of Response^7.265 Observations (or Si. , Wgts)^16  J  Analysis of Variance OF Sum of Squares Mean Squan 3^4,737650^1.57922 12^5.824550^0.48538 15^10.562200  Analysis of Variance  Numbe 4 4  4 9  Mean  8.13750 7.10000 6.88250 6.74000  J  Source^Of Sum of Squares Mean Square ^ Pattern 3^405.84787^135.283 ^ Error12^350.56562^29.214 ^ C. Total 15^756.41399  F Rath Preb s F 3,2536^0.0598  I Means for Oneway Anova Level CONTROL F3-1 F3.2 03-3  F3-2 Pattern  I Summary of Fit  Error C, Total  F3-1  I Oneway Anova  Oneway Anova  Source Pattern  CONTROL  F Ratio 4.6308  Prob > F 0.0225  Means for Oneway Anova Level^Numbe CONTROL 03.1 F3-2^4 F3-3^4  Error Lower 95% Upper 95% 8.8965 0.34835 7.3785 0.34835 6.5410 8.0590 0.34835 6.1235 7.6415 0.34835 5.9810 7.4990 Sod  Mean Std Error Lower 9591 Upper 9556 37.0975 2.7025^31.209^92.986 36.3075^2.7025^30.419^42.196 26.9900^2.7025^21.102^32.878 26.3225 2.7025^20.434^32.211  Cori Fre". "cow revle.rio.onerw...4 server varIzneA  Std Error uses a cooled estimate of error variance  Preservative III-inner I Oneway Analysis of MOR (MPa) By Pattern  Oneway Analysis of MOE (GPa) By Pattern 6.5  20 0  if 5  20  0 4.S  CONTROL  Al l Pars Tukey-Kramer 0.05  03^ Pattern  DF Sum of Squares Mean Sqtars  Rsquare^ 0.019236 Adj Rsquare^-0.22595 Root Mean Square Error^5.044192 Mean of Response^23.105 Observations (or Sion Wgts)^16  ^  F Ratio Prob F ^ 0.5455 3^0.8808500^0.293617^0.7453 12^4.7273500^0.393946 15^5.6082000  I Means for Oneway Anova Numbe 4 4 4 4  Pattern  811 Pairs Tukey-Kramer 0.05  Analysis of Variance  1 Analysis of Variance  Level CONTROL F3.1 03-2 F3-3  F3-3  Summary of Fit  Rsquare^0.157065 Adj Rsquare^-0,05367 Root Mean Square Error^0.627651 Mean of Response^5.235 Observations (cc Sion Wgts)^16  Pattern Error C. Total  F3-2  F3-1  Oneway Anova  I Oneway Anova I Summary of Fit  Source  CONTROL  Mean 5.47000 5.36250 5.25750 4.85000  1  Std Erre. Lower 95% Upper 95% 6.1538 0.31333 4.7862 0,31383 4,6787 6.0463 0.31383 4.5737 5.9413 5.5319 0.31393 4.1662  Std Error uses a cooled estimate of error variance  Source Pattern Error C. Total  DF Sum of Squares Mean Square 3^5.98850^1.9962 12^305.32650^25.4439 15^311.31500  F Ratic Prob u F 0.0785^0.9705  Means for Oneway Anova Numbe Mean Std Error Lower 9591 Level 18.277 CONTROL 4 23.7725 2.5221 2.5221 18.162 03-1 4 23.6575 03-2 4 22.5275 2.5221 17.032 F.3.3 4 2.5221 22.4625 16.967 Std Fn., IMP< a nnoierl P,tomato of error variance  PPer 95% 29.269 29.153 28.023  27.958  - 126 -  Appendix D4 Preservative IV-outer Oneway Analysis of MOE (GPa) By Pattern  Oneway Analysis of MOR (MPa) By Pattern 45  85  40 5  35 30-  6.5 25  6  20  5.5 CONTROL  F4-1  -2  F4-3  Pattern  I  15  All Pars TukerKrarner 0.05  All Pairs Tukey-Kramer 0.05  Rsquare^0.336044 Ad) Rolla/we^0.170056 Root Mean Square Error^6.071201 Mean of Response^31.66312 Observations (or Sum Wgts)^16  Analysis of Variance  I Analysis of Variance  ^ ^ F Rem Prob s F Of Sum of Squares Mean Square Source ^ ^ 3^223.86602^74.6220 Pattern 2.0245 ^0.1642 ^ Error 12^442.31373^36.8595 ^ C. Total 15^666.17974  OF Suer of Squarer Mean Square ^F Rabe Prob F 3^9.733050^3.24435^11.0448^0,0009 12^3.524950^0.29375 IS^13.258000  Means for Oneway Anova  I Means for Oneway Anova  F4-2 F4-3  F4-3  I Summary of Fit  Rsquare^0.734127 Adj Rsquare^0.667658 Root Mean Square Error^0.541983 Mean of Response^6.865 Observabons (or Sum Woes)^16  Numbe 4 4 4 4  F4-2  Oneway Anova  Summary of Fit  Level CONTRCI.  F4-I Pattern  Oneway Anova  Source Pattern Eno( C. Total  CONTROL  Mean 8.13750 6.56250 6.01500 6.82500  Level^Numbe^Mean Sod Error Lower 95% Upper 95% CONTROL^4^37,0975 3.0356^30.483^43.712 F4-1^4^33.1750^3.0356^26.561^39,789 F4.2^4^28.0825 3.0356^21.468^34.697 F4-3^4^28.2975 3.0356^21.693^34,912  Std two Lower 95% Upper 95% 0.27099 8_7279 7.5471 0.27099 5.9721 7.1529 0.27099 6.6054 5.4246 0.27099 6.2346 7.4154  Std Error uses a cooled estimate of error vanance  Std Error uses a pooled estimate of error variance  Preservative IV-inner Oneway Analysis of MOE (GPa) By Pattern  Oneway Analysis of MOR (MPa) By Pattern  6  5.5  24  n.  0  0 20  /8 3.5  CONTROL  F4-2  F4-1 Pattern  F4-3  All Pairs Tukey-Kranser 0.05  I Oneway Anova  F4-2 Pattern  All Pairs Tukey-Kramer 0.05  I Summary of Fit  Rsquare^0.364558 Adj Rsquare^0.205697 Root Mean Square Error^0.569089 Mean of Response^4.89375 Observations (or Sum Writs)^16  Rsquare^ 0.33338 Ad) Rsquare^0.166725 Root Mean Square Error ^2.796323 Mean of Response^21.1275 Observations (or Sum Writs)^16  Analysis of Variance OF Sum of Squares Mean Square 3^2.2296250^0.743208 12^3.8863500^0.323862 15^6.1159750  CONTROL  Oneway Anova  Summary of Fit  Source Pattern Error C. Total  16  I Analysis of Variance F Rabic Prob s F 2.2948^0.1298  I Means for Oneway Anova  ^ ^ F Ratic Prob F OF Sow of Squarer Mean Square Source ^ ^ Pattern 20004^0.1676 3^46,92645^15.6422 Err.",^12^93 83305^7.8194 ^ C. Total 15^140.75950  Means for Oneway Anova  Level^Numbe^Mean Std Eno. Lower 95% Upper 95% CONTROL^4 5.47000 0.28454^4.8500^6,09120 F4-1^4^4.97750 0.28454^4.3575^5.5975 F4-2^4 4.58000 0.28454^3.9600^5.2000 F4-3^4 4.54750 028454^3.9275^5.1675  Level^Numbe^Mean Sod Erro lower 959E Upper 95% CONTROL^4^23.7725 1.3982^20.726^26.819 F4.1^4^21.1650^1.3982^18.119^24.211 F42^4^19.0325 1.3982^15.986^22.079 F4-3^4^20.5400 1.3992^17.494^23.586  Sod Enor uses a pooled estimate of error variance  Std Error uses a cooled estimate of error varance  - 127 -  Appendix D5 Preservative V-outer  1  Oneway Analysis of MOE (GPa) By Pattern 8.5-  Oneway Analysis of MOR (MPa) By Pattern 45  B-  40  7.57-  1: 5  35  z rr  ^6.5-  30  0  ;  625  5.55  CONTROL^F5-1^F5-2^F5-3 Pattern  20 ^  All Pairs Tukey-Krarner 0.05  F5-2  F5-3  All Pairs Tukeyd0arner 0.05  Oneway Anova  I Summary of Fit  I Summary of Fit  Rsquare^0.791857 Ad) Rsquare^0.739821 Root Mean Square Error^0.585867 Mean of Response^6.791875 Observations (or Sum Wgts)^16  Rsquare^0.513531 Ad3 Rsquare^0.391913 Root Mean Square Error^5.283232 Mean of Response^30.28 Observations (or Sum rigts) ^16  [Analysis of Variance  ^ ^ DF San of Squares Mean Squart^F Ratic Prob F Source ^ ^ Pattern 3^15.669769^522326^15.2175^0.0002 ^ ^ Error 12^4.118875^0.34324 ^ ^ C. Total 15^19.788644  [ Means for Oneway Anova CONTROL F5-I F5.2 F5.3  F5-1 Pattern  Oneway Anova  Level  CONTROL  Numbe 4 4 4 4  Mean Std Erro Lower 95% Upper 95% 8.13750 0.29293 7,4993 8,7757 6.6568 7.9332 7.29500 0.29293 5.3968 6.03500 0.29293 6.6732 5.66000 0.29293 6.2982 5.0218  [ Analysis of Variance ^ ^ Source OF Sum of Squares Mean Squart F Ratic Prob F ^ ^ 3^353.59315^117,661 Pattern 4.2225^0.0296 ^ Error 12^334.95045^27.913 ^ C. Total 15^699.53360  I Means for Oneway Anova  Level^Numbe^Mean Std Erro Lower 9541 upper 95% CONTROL^4^37.0975 2,6416^31,342^42.853 F5-1^4^30,5250 2.6416^24.829^36.341 F5.2^4^29.5875^2.6416^23,832^35,343 F5-3^4^23.8500 2.6416^18.094^29.606  Std Error uses a pooled estimate of error variance  Std Error uses a 000fed estimate of error variance  Preservative V-inner 1 I Oneway Analysis of MOR (MPa) By Pattern  Oneway Analysis of MOE (GPa) By Pattern  30^ 27.55.5  0  0  z  17.5 -  CONTROL^F5-  2  Al Pairs Tulsey-Kramer 0.05  ^  OF Sum of Squarer Mean Square ^ 3^3.9317250^1.11391 Pattern ^ Error 17^1.6044500^0.13370 ^ IS^5.0361750 C. Total  I Means for Oneway Anova Level CONTROL F5-1 F5.2 F5-3  Numbe 4 4 4 4  Rsquare^0.128467 Ad) Rsquare^0.285589 Root Mean Square Error ^0.953833 Mean of Response^22.94125 Observations (or Sum Wgts)^16  I Analysis of Variance  ^ F Ratio Prob F Source ^ Pattern 8.5555^0.0026 Error C. Total  Mean Std Erro Lower 9591 Upper 95.4 5.47000 0.18283 5.0717 5.8683 5,22500 018203 4.8267 5,6233 5.60750 0.18283 5.2092 6,0058 4,11250 0,18283 4.0142 4,8108  Std Error uses a ooc4ed estimate of error variance  Pattern  All Pairs Tutey-Kramer 0,05  1 Summary of Fit  Rsquare^0.681415 Ad) Rsquare^0.601769 Root Mean Square Error^0.365656 Mean of Response^5.17875 Observations (or Sum Wqts) ^16 Source  CONTROL^F5-i.^FS-2  Oneway Anova  [ Oneway_Anova I Summary of Fit  I Analysis of Variance  15  ^ F Rao< Prob F OF Sum of Squares Mean Squart ^ 3^79.49283^26.1643 2.9987^0.0728 12^104,70155^8.7251 . 15^183.19938  I Means for Oneway Anova  Level^Numbe^Mean Std Erro Lower 95% Upper 95% CONTROL^4^23.7725 1.4769^20.555^26.990 F5-I^4^21,2925^1.4769^21.575^28.010 F5-2^4^24.0400 1.4769^20.822^27.258 F5-3^4^19.1600 1.4769^15.942^22.378  Std Error uses a Pooled estimate of error variance  - 128 -  Appendix D6 Preservative VI-outer Oneway Analysis of MOE (GPa) By Pattern  Oneway Analysis of MOR (MPa) By Pattern  85  45  40 7.5 35  2  30  25  5 CONTROL  F6-1  F6-2  F6-3  20  All Pairs  CONTROL  TukerKrarner  I Oneway Anova I Summary of fit  F6-2  F6.1  0.05  Pattern  Summary of Fit 0.52314  Rsquare^ 0.265926  Adj Rsquare^0.403925  Adj Rsquare^0.082408  Root Mean Square Error^0.694715  Root Mean Square Error ^5.879667  Mean of Response^7.29875 Observations (or Sum Wgts) ^16  Mean of Response^33.04062 Observatons (or Stan Wpm) ^16  I Analysis of Variance ^ DF Sum of Squares Mean Square F Ratio Prob > 9 ^ ^ Pattern 3^6.353625^2.11788 4.3882^0.0265 ^ Error 12^5.791550^0.48263 ^ C. Total 15^12.195175 ^  I Analysis of Variance  ^ ^ DF Sum of Squaree Mean Square F Ram Prob > F ^ ^ Pattern 3^150.28247^50.0942 1,4490^0.2775 ^ Error 12^414.84583^39.5705 ^ C. Total 15^565.12829  Source  I Means for Oneway Anova  I Means for Oneway Anova Numbe  Mean  Std Eno.  CONTROL  4  8.13750  0.34736  7.3807  8.8943  F6-1  4 4  7.65750  0.34736  F6-2  6.84000  0.34736  6.9007 6.0832  8.4143 7.5968  96-3  4  6.56000  0.34736  5,8032  7.3168  Level  AU Pairs  I Oneway Anova  Rsquare^  Source  F6-3  Tukey-Kramer  0.05  Pattern  Lower 959k Upper 95%  Std Error uses a pooled estimate of error variance  Level^Numbe^Mean Std Erro Lower 9541 Upper 95% ^ CONTROL^4^37.0975 2.9398 30.692^43.503 ^ F6.1^4^34.8700 2.9398 28,465^41.275 ^ 96-2^4^30.5675 2.9398 24.162^36.973 ^ F6.3^4^29.6275 2.9398 23.222^36,033 Std Error uses a pooled estimate of error variance  Preservative VI-outer I Oneway Analysis of MOE (GPa) By Pattern  Oneway Analysis of MOR (MPa) By Pattern  .5  35 30  5 0  20 5  15  All Pales  F6-  CONTROL  10 CONTROL  F6 - 2  F6-1  Tukey -1,, e(oe' 0.05  Pattern  I  Oneway Anova  Pattern  Tukev-Kramer 0,05  I Summary of Fit  Rsquare^ 0.419201  Rsquara^ 0,513736  Adj Rsquare^0.274001  Adj Rsquare^0.39217 Root Mean Square Error^4.110111  Root Mean Square Error^0.510967 Mean of Response^5.16375  Mean of Response^22,16375 Observations (or Sum Wots)^16  Observations (or Sum Wgtsj^16  I Analysis of Variance  I Analysis of Variance  ^  ^ OF Sum of Squarer Mean Square F Ratx Pro!, F ^ ^ ^ 3^2.2613250^0.753775 2.8871 0.0796 Pattern ^ Error 12^3.1330500^0.261087 ^ C. Total 15^5.3943750  I Means for Oneway Anova Numbe  Mean  CONTROL  4  5.47000  0.25598  F6-1  4 4  5.59500  F6, 2  4.71250  F6-3  4  4.87750  Level  All Parrs  Oneway Anova  I Summary of Fit  Source  F6-3  Std Erro Lower 9594 Upper 95% 4.9133  6.0267  0.25548 0.25548  5,0383 4.1555  6.1517  0.25598  4.3208  5.4342  Std Error uses a cooled estimate of error variance  5,2692  ^ ^ RatK Pf Ob F DF Su m of Squares Mean Square ^ ^ 3^214.20023^71.4001 9.2260^0 0296 Pattern ^ Error 12^202.79575^16.8955 ^ C. Total 15^416.91598  Source  I Means for Oneway Anova  ^ Mean Sad Erro Laver 95* Upper 95% Level^Numbe ^ CONTROL^9 23.7725 2.0552^19.295^28.250 ^ F6.1^4 27.3950 2.0552^22.917^31.873 ^ F6-2^4 19.0625 2.0552^14.585^23.540 ^ F6-3^4 18.425D 2.0552^13.947^22.903  Std Error uses a 000led estimate of error variance  - 129 -  Appendix D7 One-way analysis of internal bonding properties Oneway Analysis of MOE (GPa) By Pattern  Oneway Analysis of MOR (MPa) By Pattern  8.5 -  45 ^  840 75J  35  7-  se^6.5-  30  5  625  5.55 CONTROL.  F6-1  F6-3^All Pan Tukerkrarner  F6.2  20 CONTROL  F6-1  Pattern  F6-2  All Parrs 0.05  Pattern  I Oneway Anova  Oneway Anova  I Summary of Fit  I Summary of Fit  0.52314  Rsquare^ 0.265926  Adj Rsquare^0.403925 Root Mean Square Error^0.694715  Adj Rsquare^0.082108  Rsquare^  F6-3  Tukey•Krarner  0.05  Root Mean Square Error ^5.879667 Mean of Response^33.04062  Mean of Response^7.29875 Observations (or Sum Wilts)^16  Observations (or Sum Wilts) ^16  I Analysis of Variance  I Analysis of Variance  Source  DF Sum of Squares Mean Square  Rabc Prob F  Pattern Error  3^6.353625^2,11738 12^5.791550^0.48263  43882^0.0265  C. Total  15^12.145175  Source  OF Sum of Squares Mean Square  F Rater Rob a F  Pattern  3^150.28247^50.0942 12^414.84583^34.5705  1.4490^0.2775  Error C. Total  15^565.12829  I Means for Oneway Anova  I Means for Oneway Anova Nurnbe  Mean  Std Env. Lower 955k Upper 95%  Level^Nurnbe^Mean Std bro. Lower 9591 Upper 95%  CONTROL  4  8.13750  0.34736  7.3807  8.8943  CONTROL^4 37.0975 2.9398^30.692^43 503  F6.1 F6-2  4  7.65750  0.34736  6.9007  8,4143  4  6.84000  0.34736  6.0832  7 5968  F6-1^9^34.8700 2.9398^28.465^41.275 F64^4^30.5675 29398^24.162^36.973  F6-3  4  6.56000  0.34736  5.8032  7.3168  Level  Std Error uses a ponied estimate of error vanance  Preservative I- IB  F6-3^4^29.6275 2.9398^23.222^36.033 Std Errol uses a pooled estimate of error variance  Preservative II- IB  Appendix D8 One-way analysis of internal bonding properties-continued Oneway Analysis of IB (MPa) By Treatment  Oneway Analysis of 1E1 (MPa) By Treatment  0.5-  0.5- ^ 0.45-  045-,  0.35 -  0 35 -  0.4.  0.3 -  0 3-*  0 -  0.25-'  0.2 -  0.2-■ 0.15  0.15 01  Control^r^F3-1^F3-2 Treatment  0.1  F3-3^All Pairs^ Tukey-Krarner 0.05^  Control^F4-1^F4-2^4 Treatment  F4-3^All Pairs Tukey-Kramer 0.05  Oneway Anova  Oneway Anova  [ Summary of Fit  I Summary of Fit  Rsquare^0.571127 Ad) Rsquare^0.557143 Root Mean Square Error ^0.057398 Mean of Respoc e^0.323208 Observations (or Sum Wgts)^96  Rsquare^0.467866 Ad) Rsquare^0.450514 Root Mean Square Error ^0 066429 Mean of Response^0.309198 Observabons (or Sum Worts)^96  [ Analysis of Variance  I Analysis of Variance Source^OF^Sun) of Squares Mean Squart Treatment^3^0.35694903^0.118983 Error^92^0,40598021^0.004413 C. Total^95^0.76292924  F Ratic^Prob > F^ 26.9630^s.0001^  F Ratio^Prob > F 40,8387^x.0001  I Means for Oneway Anova  1  I Means for Oneway Anova  Source^OF^Sum of Square Mean Squaw Treatment^3^0.40292350^0,134308 Error^92^0.30256433^0.003289 C. Total^95^0,70548783 Level Control F4-1 F4-2 F9-3  Level^Number^Mean^Std Erro. Lower 954E Upper 95% 0.43693 0.38307 Control 24 0.410000 0.01356 F3-1 24 0-253542 0.01356 0.22661 0.213047 F3-2 24 0.269375 0.01356 0.24244 0.29631 F3-3 29 0.303875 0,01356 0.27694 0.33081  umber 24 24 24 24  Mean 0.410000 0.347750 0.302583 0.232500  Sid Error Lower 9544 Upper 95% 0.43325 0.38675 0.01171 0,01171 0.32450 0.37100 0.01171 0.27933 0.32583 0.01171 0.20925 0.25575  Std Error uses a pooled estimate of error variance  Std Error Use a cooled estimate of error variance  Preservative III- IB  Preservative IV- IB  Oneway Analysis of TB (MPa) By Treatment  Oneway Analysis of 111 (MPa) By Treatment  0,5 0.45-■ 0,4 0,35-; ea  035-, 0.3-  0.25-■ 0-20.157 0  2  Conool^F5-1  F5-3  Tieatment  MI Pain Tukey-Kramer 0,05  l Oneway Anova  Summary of Flt Rsquare^0.565797 Ad) Rsquare^0.551638 Root Mean Square Error^0.054143 Mean of Response^0.315375 Observations (or Sum Wgts)^96  I Analysis of Variance ^ Source OF Sum of Squares Mean Square ^F Raw Prob > F ^ Treatment 3^0.35143483^0.117145 39.9608^v.0001 ^ Error 92^0.26969767^0.002931 ^ 95^0.62113250 C. Total  I Means for Oneway Anova  F6-1^F6.2  AM Pairs Tukey-Kramer 0,05  F6-3  Treatment  I Oneway Anova  Summary of Fit Rsquare^0.518589 Ad) Rsquare^0.502374 Root Mean Square Error^0.05665 Mean of Response^0.338625 Observations (or Sum Wgts)^96  Analysis of Variance  ^ OF Sun) of Squares Mean Squaw^F Rabe Prob F Source ^ Treatment 3^031741658^0.105806 32.9688^s.0001 ^ 92^029525192^0.003209 Error ^ C. Total 95^0.61266850  I Means for Oneway Anova  1  Level^Number^Mean Std Erro Lower 9544 Upper 95% ^ 0,43195 Control^24 0-410000 0.01105^0.38805 ^ 0.31320 F5-1^24 0.291250 0.01105^0.26930 ^ F5-2^24 0.316333 0.01105^0.29438 0.33828 ^ 0.26587 F5-3^24 0.243917 0.01105^0.22197  Level^Number^Mean^Std Erro Lower 9541 Upper 95% 0.43297 Control 0.38703 24 0.410000 0.01156 F6-1 24 0.380292 0.01156 0.35733 0.40326 24 0.280375 0.01156 0.25741 F6-2 0.30334 F6-3 24 0.283833 0.01156 0,26087 0.30680  Std Error uses a pooled estimate of error variance  Std Error uses a pooled estenate of error variance  Preservative V- IB  Preservative VI- IB  - 131 -  ^  Appendix E "One-way analysis of decay resistance properties" Appendix El One-way analysis of mass loss (%) by P placenta  Oneway Analysis of Mass loss (%) By Sample 50  0  40 •  in  -  0  30 20 10  ills.^Ise^i  0  ll  ,  1^1^1^1^1^1^1^1^1^1^1  C-OSBF1-1 Fl-3 F2-2 F3-1 F3-3 F4-2 F5-1 F5-3 F6-2 ZnE All Pairs C-pineF1-2 F2-1 F2-3 F3-2 F4-1 F4-3 F5-2 F6-1 F6-3 Tukey-Kramer 0.05 Sample^  Oneway Anova  I Summary of Fit Rsquare  0.982497  Adj Rsquare  0.980982  Root Mean Square Error Mean of Response  1.663276 5.522937  Observations (or Sum Wgts)  252  Analysis of Variance Source DF ^Sum of Squares Mean Square Sample  I  20  Error  231  C. Total  251  ^  F Ratio  Prob > F  35872.948^1793.65^648.3487  <.0001  639.058^2.77 36512.006  Means for Oneway Anova Level  Number  Mean  Std Error  Lower 95%  C-OSB  12  36.3350  0.48015  35.389  37.281  C-pine  12  47.3017  0.48015  46.356  48.248  Upper 95%  F1-1  12  1.5008  0.48015  0.555  2.447  F1-2  12  0.9958  0.48015  0.050  1.942  F1-3  12  0.8808  0.48015  -0.065  1.827  F2-1 F2-2  12 12  1.9167  0.48015  0.971  2.863  1.8225  0.48015  0.876  2.769  F2-3  12  1.7775  0.48015  0.831  2.724 2.899  F3-1  12  1.9533  0.48015  1.007  F3-2  12  1.7667  0.48015  0.821  2.713  F3-3  12  1.9600  0.48015  1.014  2.906  F4-1  12  1.8242  0.48015  0.878  2.770  F4-2  12  1.2417  0.48015  0.296  2.188  F4-3 F5-1  12 12  0.8192 2.2808  0.48015 0.48015  -0.127 1.335  1.765 3.227 2.424  F5-2  12  1.4783  0.48015  0.532  F5-3  12  0.6675  0.48015  -0.279  1.614  F6-1  12  5.1275  0.48015  4.181  6.074 2.573  F6-2  12  1.6267  0.48015  0.681  F6-3  12  0.5250  0.48015  -0.421  1.471  ZnB  12  2.1800  0.48015  1.234  3.126  Std Error uses a pooled estimate of error variance  Appendix E2 One-way analysis of mass loss (%) by G trabeum Oneway Analysis of Mass loss (%) By Sample 50 0  40 30  0  0 CO  20 10  1 I^•^1^1^11 ^1  0  .  1111111  C-OSBF1-1 F1-3 F2-2 F3-1 F3-3 F4-2 F5-1 F5-3 F6-2 ZnE All Pairs C-pineF1-2 F2-1 F2-3 F3-2 F4-1 F4-3 F5-2 F6-1 F6-3 Tukey-Kramer 0.05 Sample^  Oneway Anova I Summary of Fit Rsquare^  0.983175  Adj Rsquare^  0.981718  Root Mean Square Error^1.425063 Mean of Response^4.98873 Observations (or Sum Wgts)^252  Analysis of Variance Source  ^  DF Sum of Squares Mean Square ^F Ratio Prob > F ^ Sample 20^27412.891^1370.64 674.9273^<.0001 ^ Error 231^469.116^2.03 ^ C. Total 251^27882.007  Means for Oneway Anova Number  Mean  Std Error  Lower 95%  C-OSB  12  29.5850  0.41138  28.774  30.396  C-pine  12  43.1933  0.41138  42.383  44.004 2.861  Level  Upper 95%  F1-1  12  2.0500  0.41138  1.239  F1-2  12  0.6775  0.41138  -0.133  1.488  F1-3  12  0.1392  0.41138  -0.671  0.950  F2-1  12  3.0992  0.41138  2.289  3.910  F2-2  12  2.0867  0.41138  1.276  2.897  F2-3  12  1.6550  0.41138  0.844  2.466  F3-1  12  3.3075  0.41138  2.497  4.118  F3-2  12  2.1233  0.41138  1.313  2.934  F3-3  12  1.5408  0.41138  0.730  2.351  F4-1  12  1.9517  0.41138  1.141  2.762  F4-2  12  1.4817  0.41138  0.671  2.292  F4-3  12  1.2500  0.41138  0.439  2.061 2.205  F5-1  12  1.3942  0.41138  0.584  F5-2  12  0.8492  0.41138  0.039  1.660  F5-3  12  0.4808  0.41138  -0.330  1.291  F6-1  12  2.5875  0.41138  1.777  3.398  F6-2  12  1.6308  0.41138  0.820  2.441  F6-3  12  1.4417  0.41138  0.631  2.252  ZnB  12  2.2383  0.41138  1.428  3.049  Std Error uses a pooled estimate of error variance  Appendix E3 One-way analysis of mass loss (%) by T versicolor Oneway Analysis of Mass loss (%) By Sample 40  0  30  0 0 20 10 0 I^I^I^I^I^III! C-OSBF1-1 F1-3 F2-2 F3-1 F3-3 F4-2 F5-1 F5-3 F6-2 ZnE All Pairs C-poplE1-2 F2-1 F2-3 F3-2 F4-1 F4-3 F5-2 F6-1 F6-3 Tukey-Kramer 0.05 Sample^  Oneway Anova Summary of Fit Rsquare  0.976233  Adj Rsquare  0.974176  Root Mean Square Error Mean of Response  1.471317 4.96369  Observations (or Sum Wgts)  I  252  Analysis of Variance Source Sample Error C. Total  DF  Sum of Squares  Mean Square  F Ratio  Prob > F  20 231  20540.413  1027.02  474.4240  <.0001  500.063  2.16  251  21040.476  Means for Oneway Anova Level  Number  Mean  Std Error  Lower 95%  Upper 95%  C-OSB  12  0.42473  23.904  C-poplar  12  24.7408 38.7367  0.42473  37.900  25.578 39.574  0.527 0.390  2.201  -0.031 3.567 2.728  1.643 5.241 4.402  F1-1  12  1.3642  0.42473  F1-2  12  1.2267  0.42473  F1-3  12  0.8058  0.42473  F2-1 F2-2  12 12  4.4042 3.5650  0.42473 0.42473  F2-3 F3-1  12  2.4300  0.42473  5.0125  0.42473  1.593 4.176  3.267  12  F3-2  12  2.3008  0.42473  1.464  3.138  F3-3 F4-1  12 12  1.8033 1.7700  0.42473 0.42473  0.966  2.640  0.933  2.607  F4-2  12  1.7167  0.42473  0.880  2.554  F4-3  12 12  1.1942 2.0692  0.42473 0.42473  0.357 1.232  2.031 2.906 2.149  2.064  5.849  F5-1 F5-2  12  1.3125  0.42473  0.476  F5-3  12  0.9600  0.42473  0.123  1.797  F6-1  12  0.42473  3.342  5.016 2.887  F6-2  12  4.1792 2.0500  0.42473  1.213  F6-3  12  0.4917  0.42473  -0.345  1.329  ZnB  12  2.1042  0.42473  1.267  2.941  Std Error uses a pooled estimate of error variance  Appendix E4 One-way analysis of mass loss (%) by I. lacteus  I Oneway Analysis of Mass loss (%) By Sample 60 50  0  ra  0  E  40  0  30 20 10  ;  i  I  -  0  I ^$^I  :^I  tl  III C-OSBF1-1 F1-3 F2-2 F3-1 F3-3 F4-2 F5-1 F5-3 F6-2 ZnE All Pairs C-popI51-2 F2-1 F2-3 F3-2 F4-1 F4-3 F5-2 F6-1 F6-3 Tukey-Kramer 0.05 Sample^  Oneway Anova Summary of Fit Rsquare^  0.969431  Adj Rsquare^ 0.966784 Root Mean Square Error^2.145749 Mean of Response^7.594643 Observations (or Sum Wgts)^252  Analysis of Variance Source  ^  DF Sum of Squares Mean Square^F Ratio Prob > F ^ 20^33728.614^1686.43 366.2777^<.0001 Sample ^ Error 231^1063.580^4.60 ^ C. Total 251^34792.194  Means for Oneway Anova Level  Number  Mean  Std Error  Lower 95%  C-OSB  12  35.7233  0.61942  34.503  36.944  C-poplar  12  46.2408  0.61942  45.020  47.461  F1-1  12  4.8783  0.61942  3.658  6.099  F1-2  12  3.5842  0.61942  2.364  4.805  Upper 95%  F1-3  12  0.3567  0.61942  -0.864  1.577  F2-1 F2-2  12 12  15.1958 10.9250  0.61942 0.61942  13.975 9.705  16.416 12.145  F2-3  12  9.4625  0.61942  8.242  10.683  F3-1  12  7.2483  0.61942  6.028  8.469  F3-2  12  6.0983  0.61942  4.878  7.319  F3-3  12  2.4725  0.61942  1.252  3.693  F4-1  12  1.5692  0.61942  0.349  2.790  F4-2  12  1.5583  0.61942  0.338  2.779  F4-3 F5-1  12 12  0.6833 1.7058  0.61942 0.61942  -0.537 0.485  1.904 2.926  F5-2  12  1.5183  0.61942  0.298  2.739  F5-3  12  1.3950  0.61942  0.175  2.615  F6-1  12  3.4892  0.61942  2.269  4.710  F6-2  12  2.2217  0.61942  1.001  3.442  F6-3  12  1.0550  0.61942  -0.165  2.275  ZnB  12  2.1058  0.61942  0.885  3.326  Std Error uses a pooled estimate of error variance  

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