Date of Award
5-2025
Degree Type
Honors College Thesis
Academic Program
Polymer Science and Engineering BS
Department
Polymers and High Performance Materials
First Advisor
Sarah E. Morgan, Ph.D.
Advisor Department
Polymers and High Performance Materials
Abstract
Morphology plays an important role in the physical properties of block copolymer (BCP) materials. Depending on the type of morphology and chemical composition of the blocks, BCPs are used in applications ranging from soft biomaterials for biomedical devices to rigid materials for ballistics protection. Due to incompatibility between comonomers and required block weight ratios to achieve targeted morphologies, it is generally necessary to use complex, time-consuming, and expensive synthetic techniques to prepare BCPs. As a result, there is increased interest in the development of new processing methods to tailor block copolymer morphology without the need for additional synthesis. The morphological effects of blending polystyrene (h-PS) and polyisobutylene (h-PIB) homopolymers of varying molecular weights with poly(styrene-b-isobutylene-b-styrene) triblock copolymers were investigated. Homopolymers and triblocks were synthesized and structures confirmed via nuclear magnetic resonance spectroscopy and gel permeation chromatography. Small-angle X-ray scattering was employed to evaluate morphology and domain size. It was found that block length, molecular weight, identity of added homopolymer, and solvent all affected equilibrium morphology. Theoretical morphology predictions based on the ratio of homopolymer blended with the BCP for diblock copolymer/homopolymer blends were found to not hold for our triblock systems.
Copyright
Copyright for this thesis is owned by the author. It may be freely accessed by all users. However, any reuse or reproduction not covered by the exceptions of the Fair Use or Educational Use clauses of U.S. Copyright Law or without permission of the copyright holder may be a violation of federal law. Contact the administrator if you have additional questions.
Recommended Citation
Searles, John F., "Tuning the Morphology of Triblock Copolymers via Homopolymer Blending" (2025). Honors Theses. 1027.
https://aquila.usm.edu/honors_theses/1027