Investigating the role of polymer tacticity on the properties and filtration efficiency of poly(lactide)-modified lignin nanofibers
department or school: Science, Faculty of
department or school: Chemistry, Department of
data provider: DSpace
degree campus: UBCV
creator: Kim, Diana
issued: 2021-12-20T17:42:22Z
issued: 2021
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: The rising environmental awareness has prompted investigation of biopolymers as alternative materials to the petroleum-based and non-biodegradable plastics. One such biopolymer is lignin, the second most abundant biopolymer on Earth. Although more than 50 million tons of lignin is extracted from the wood pulping industry annually, less than 2% is used for value-added products.1 Despite its many inherent advantages, lignin has several structural or mechanical limitations to be utilized in its pristine form. Chemical modification with other biopolymers, such as poly(lactide) (PLA), is a promising way to overcome the poor processability of this underutilized material. In this thesis, lignin-graft-PLLA and lignin-graft-PDLA copolymers were synthesized and transformed into nanofibers through electrospinning. The nanofibers generated with either lignin-graft-PLLA or lignin-graft-PDLA showed XRD patterns corresponded to the homocrystallites of isotactic PLA, whereas the nanofibers generated with 1:1 v/v solution blend of lignin-graft-PLLA/lignin-graft-PDLA showed stereocomplexation of the PLA chains. The stereocomplexation resulted in a different fiber morphology by more dense chain packing and enhanced Young’s modulus and tensile strength, although sacrificing elongation at break. All lignin-graft-PLA-based nanofibers showed good filtration performances as lignin-based aerosol filters. However, stereocomplexation resulted in brittle nanofibers and higher air blockage through the filter, which was disadvantageous to be used as a mask material.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/80466
note: INVESTIGATING THE ROLE OF POLYMER TACTICITY ON THE PROPERTIES AND FILTRATION EFFICIENCY OF POLY(LACTIDE)-MODIFIED LIGNIN NANOFIBERS by Diana Kim B.Sc., The University of British Columbia, 2019 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Chemistry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) December 2021 © Diana Kim, 2021 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, a thesis entitled: Investigating the Role of Polymer Tacticity on the Properties and Filtration Efficiency of Poly(lactide)-Modified Lignin Nanofibers submitted by Diana Kim in partial fulfillment of the requirements for the degree of Master of Science in Chemistry Examining Committee: Prof. Parisa Mehrkhodavandi, Chemistry, UBC Supervisor Prof. Frank Ko, Materials Engineering, UBC Supervisory Committee Member Prof. Laurel Schafer, Chemistry, UBC Supervisory Committee Member iii Abstract The rising environmental awareness has prompted investigation of biopolymers as alternative materials to the petroleum-based and non-biodegradable plastics. One such biopolymer is lignin, the second most abundant biopolymer on Earth. Although more than 50 million tons of lignin is extracted from the wood pulping industry annually, less than 2% is used for value-added products.1 Despite its many inherent advantages, lignin has several structural or mechanical limitations to be utilized in its pristine form. Chemical modification with other biopolymers, such as poly(lactide) (PLA), is a promising way to overcome the poor processability of this underutilized material. In this thesis, lignin-graft-PLLA and lignin-graft-PDLA copolymers were synthesized and transformed into nanofibers through electrospinning. The nanofibers generated with either lignin-graft-PLLA or lignin-graft-PDLA showed XRD patterns corresponded to the ho…
has type: Thesis/Dissertation
date issued: 2022-05
is shown at: 10.14288/1.0406098
language: eng
degree discipline: Chemistry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Mehrkhodavandi, Parisa
type: Text
identifier URI: http://hdl.handle.net/2429/80466