Development of Synthetic, Pluripotent Materials by Tuning Dynamic, Thia-Michael Polymer Networks to Enable New Functionality

In 1920, Hermann Staudinger revolutionized materials science by proposing that substances like rubber and cellulose were not mere molecular aggregates but were long-chain macromolecules known as polymers. Since then, synthetic polymers such as polyethylene, polyethylene terephthalate, and nylon-6 have become integral to modern life. Advances in polymer chemistry have enabled precise control over molecular weight, architecture (linear, branched, networks), and monomer composition, allowing materials to be optimized for specific applications. For many uses, this specialization poses no obstacle, but in resource-scarce areas (in space, on the battlefield, at sea), a single material capable of adapting to multiple functions would be transformative. In nature, pluripotent stem cells can give rise to all adult cell types in the human body, creating life from a single source. Analogously, this dissertation explores single-feedstock, pluripotent polymers that can access a wide breadth of mechanical properties through external stimuli, without the need for chemical modification. In Chapter 1, the criteria for achieving pluripotency and potential pathways towards this goal will be outlined with a focus on differentiability, programmability, and stability. In Chapter 2, dynamic covalent polymer networks using catalyst-free, dynamic at room temperature, thia-Michael bonds will be combined with tempering, akin to the process in metallurgy, to demonstrate synthetic pluripotency. With a mechanistic understanding of tempering in dynamic, thia-Michael networks, a diverse range of accessible mechanical properties will be demonstrated in reprocessable, stable materials. In Chapter 3, multipotent elastomers based on thia-Michael networks will be developed to demonstrate tunability within a single application, without the need for chemical modification. In Chapter 4, salt additives will be used to transform a matrix from multipotent to pluripotent while imparting ion conductivity. In Chapter 5, a potential future additive to improve the ion conductivity of pluripotent matrices, known as an organic ionic plastic crystal, will be studied with a combined experimental and computational approach. In Chapter 6, these results will be summarized and the future of synthetic, pluripotent materials will be discussed. Additionally, all supplemental movies that are mentioned in the text are available for viewing in the attached files.