Abstract
Polyacrylamide-based materials are of interest due to their unique properties, namely their hydrophilicity. Polyacrylamides can be readily synthesized in both linear and crosslinked architectures via many different chain growth methods, and multi-component copolymers imbued with additional functionality is possible. While many commercial applications exist for polyacrylamides, their breadth of utility has not yet been discovered. Many gaps still remain; however, this dissertation serves as a report of improved properties and functionality of PAN-based carbon fiber precursors and TCA functional materials via incorporation of polyacrylamides. In this dissertation, I introduce polymers and their distinctive qualities to serve as a basis for the research described herein, followed by a discussion of the history and uses of polyacrylamides, the polymer that ties together this body of work (Chapter 1). In the same chapter, I introduce carbon fiber and supramolecular polymers, two areas of research this dissertation will cover. This is followed by an account of a novel post-polymerization method of producing both atactic and isotactic PAN/PTBAM precursors for the production of high-performance carbon fiber (Chapter 2). Next, my research on a supramolecular TCA-based polyacrylamide hydrogel designed for metal sequestration in water treatment applications is described (Chapter 3). Lastly, I conclude my dissertation with a summary and future directions of both projects (Chapter 4). Within the field of carbon fiber, over 90% of fibers are produced from PAN-based precursors, due to the high-performance capabilities this precursor allows. While much research has been done on these fibers to improve properties, there has been less focus on the precursor polymer than on fiber production and processing. Although the fiber production processes greatly affect the resultant carbon fiber’s performance, the precursor polymers used to generate fibers play a large role in these properties, as well. Currently, PAN is produced via an uncontrolled free radical polymerization, which limits control over properties like tacticity and dispersity. To reach the ultimate trifecta of simultaneous stereochemical, molecular weight, and tacticity control, we developed a novel two-step chemical process in which PTBAM is first synthesized in a manner that can yield isotactic, relatively high molecular weight (~150 kDa), and low dispersity polymers. This polymer is then subjected to a post-polymerization modification of a pseudo-dehydration reaction capable of converting the majority of amide sidechain groups to nitriles, creating a PAN/PTBAM copolymer. This conversion is stereoretentive and does not greatly affect the molecular weight distribution defined in the first step, leading to better PAN-based precursors for carbon fiber production. Both atactic and isotactic PAN/PTBAM polymers were spun into fibers and thermally processed, which were observed to have dramatically enhanced mechanical properties (e.g., stiffness and strength, and counterintuitively the elasticity) compared to commercially purchased Sigma PAN precursors of a similar molecular weight treated in the same manner. In terms of supramolecular chemistry, TCAs have garnered attention for their binding ability of soft metal ions. This leads to questions of whether these compounds could be useful in remediation of metal-laced water sources. Two highly toxic metals, mercury and lead, have shown to be compatible with TCA binding. While research has been done into these types of interactions, many of these technologies have not been realized as functional materials. A need for robust and selective materials capable of metal binding is seen in water treatment applications. Within, I describe functionalization of a thiacalix[4]arene core to improve soft metal binding and hydrophilicity, as well as addition of an acrylamide polymerizable group, allowing for incorporation into a polyacrylamide-based hydrogel network. This allowed for production of a functional proof- of-concept material that is able to selectively sequester metal ions, specifically silver, mercury, and lead ions from water sources. Overall, this dissertation demonstrates the scope of polyacrylamide architectures and applications that are readily accessible and presents two novel applications that illustrate this breadth.
Committee Chair
Jonathan Barnes
Committee Members
Christopher Cooper; Kevin Moeller; Timothy Wencewicz; Vladimir Birman
Degree
Doctor of Philosophy (PhD)
Author's Department
Chemistry
Document Type
Dissertation
Date of Award
11-6-2025
Language
English (en)
DOI
https://doi.org/10.7936/te55-cq84
Recommended Citation
Trick, Tarryn, "Synthesis of Well-defined Acrylamide-based Polymers and Related Materials for Water Treatment and the Fabrication of Carbon Fiber" (2025). Arts & Sciences Theses and Dissertations. 3692.
The definitive version is available at https://doi.org/10.7936/te55-cq84