Abstract:

Polymer blending offers a promising approach to developing new materials with unique properties by combining existing plastics. However, most polymers are thermodynamically immiscible with each other, resulting in poor interfacial adhesion and compromised mechanical properties. Additives known as compatibilizers can improve the performance of these blends, but conventional strategies are often limited by their specificity to individual polymer blends or complex synthetic requirements. My dissertation explores how different molecular and network architectures can be utilized to improve the versatility of compatibilizers for immiscible polymer blends.  First, my work investigates a miktoarm star copolymer containing three chemically distinct polymer arms as a nonreactive compatibilizer, demonstrating improvements in mechanical properties and morphological stability across multiple binary and ternary polymer blends. Next, it explores thermally reversible Diels–Alder chemistry as an alternative compatibilization strategy, culminating in the development of an in situ reactive extrusion method that forms a dynamically crosslinked network, significantly improving the toughness and ductility of several immiscible polymer blends. Together, these studies highlight how controlling polymer architecture and dynamic network formation can enable more versatile and accessible compatibilization strategies with potential applications in mixed-plastic recycling.