Date of Award

Spring 4-26-2022

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

School

Polymer Science and Engineering

Committee Chair

Derek L. Patton

Committee Chair School

Polymer Science and Engineering

Committee Member 2

Sergei Nazarenko

Committee Member 2 School

Polymer Science and Engineering

Committee Member 3

Robson F. Storey

Committee Member 3 School

Polymer Science and Engineering

Committee Member 4

Yoan C. Simon

Committee Member 4 School

Polymer Science and Engineering

Committee Member 5

Jason D. Azoulay

Committee Member 5 School

Polymer Science and Engineering

Abstract

Thermoset polymer networks are ubiquitous in the construction of high-performance materials due to their excellent mechanical properties, solvent resistance, and thermomechanical performance. However, the crosslinked structure that instills these materials with favorable performance also makes them incredibly resistant to degradation and are nearly impossible to recycle – adding to the ever-growing problem of plastic pollution. Hydrolytically degradable thermosets have emerged as a potentially sustainable alternative to traditional thermosets by affording networks that are inherently degradable in aqueous environments. This dissertation focuses on the development of hydrolytically degradable thermoset networks with tunable degradation behavior through the implementation of ketal-based crosslinks. Given the wide range of ketal monomer structures in conjunction with highly modular step-growth polymerization methods provides the ability to tailor network hydrolytic stability and thermomechanical performance of thermoset networks.

Chapter I of this dissertation introduces the fundamentals of thermoset networks and establishes the need for hydrolytically degradable thermoset alternatives for traditional thermoset products as well as thermoset-based carbon fiber composite materials. Chapter II focuses on hydrolytically degradable poly(β-thioester ether ketal) using radical-mediated thiol-ene photopolymerization and investigates the effect of acyclic ketal crosslink structure on network degradation behavior and thermomechanical properties. Chapter III then extends the work in the previous section into the implementation of cyclic ketal crosslinks and their effect on the hydrolytic stability of poly(β-thioester ether ketal) networks. Finally, Chapter IV investigates ketal-based epoxy amine networks as the degradable matrix component of recyclable carbon fiber reinforced polymer composites.

ORCID ID

0000-0003-3689-9719

Available for download on Monday, May 01, 2023

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