Date of Award

Fall 12-2021

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

School

Polymer Science and Engineering

Committee Chair

Jason D. Azoulay

Committee Chair School

Polymer Science and Engineering

Committee Member 2

Derek L. Patton

Committee Member 2 School

Polymer Science and Engineering

Committee Member 3

Yoan C. Simon

Committee Member 3 School

Polymer Science and Engineering

Committee Member 4

Xiaodan Gu

Committee Member 4 School

Polymer Science and Engineering

Committee Member 5

Zhe Qiang

Committee Member 5 School

Polymer Science and Engineering

Abstract

Aromatic polymers–those that contain planar, rigid aromatic, or pseudo-aromatic heterocycles–display robust chemical, mechanical, and thermal properties. This enables their broad utility in commodity, specialty, and high-performance applications. However, the harsh conditions and reagents utilized to access these materials, typically through step-growth reaction methodologies, has fundamentally restricted access to molecularly complex and functional derivatives of these materials. Metal-mediated synthetic approaches toward these materials have matured to high levels in recent years, allowing access to contemporary aromatic polymers under facile reaction conditions. Nevertheless, these methodologies ubiquitously suffer from limitations imparted through the transition metal catalysts they employ, such as intolerance toward functionality, rigorous monomer synthesis and purification, air and water intolerance, lack of orthogonality, and limited achievable molecular complexity. Accordingly, there remains a fundamental need for novel approaches toward accessing aromatic polymers to expand these products toward applications in current and future technologies. Homogenous gold complexes have recently emerged as excellent catalysts in numerous transformations involving the activation of unsaturated carbon bonds towards the attack of a wide variety of nucleophiles under facile conditions. However, despite its utility, these reactions remain effectively nascent in polymer science and correspondingly toward the synthesis of next-generation aromatic polymers.

Chapter I introduces important concepts and limitations related to the synthesis of aromatic polymers, in addition to an introduction to the fundamentals of homogenous gold catalysis, contemporary reaction protocols, and its effectively unexplored nature in polymer science. Chapter II outlines a comprehensive mechanism-based optimization and characterization approach toward the extension of gold-catalyzed intermolecular hydroarylation reactions in the synthesis of novel aromatic polymer systems. Chapter III demonstrates the utility of this gold-catalyzed polymerization approach toward synthesizing molecularly complex polymers comprising a variety of backbone structures and pendant functionalities. Chapter IV employs the robust reactivity of the Au-catalyzed transformations developed in Chapters II–III toward the post-polymerization modification of unfunctionalized commodity and specialty aromatic polymers. This approach is further leveraged in Chapter V toward the formation of polymer networks from commodity aromatic polymers via a cascade gold post-polymerization modification crosslinking reaction.

ORCID ID

0000-0003-0494-5944

Available for download on Sunday, July 28, 2171

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