Honors Theses
Permanent URI for this collectionhttps://hdl.handle.net/10217/240482
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Item Open Access Novel application of chain transfer agents for generation of high value polymers during mechanical recycling(Colorado State University. Libraries, 2024) Wilusz, Gwen, author; Estock, John, author; Hill, Megan, authorPlastic consumption has increased drastically in the modern era, inevitably leading to an increase in plastic waste. While recycling was historically proposed to counteract this influx, the combination of the heating and shearing forces innate to this process leads to the formation of highly reactive, short-lived radical species that can induce chain degradation of polymers. This decreases the overall molecular weight of the material, inevitably resulting in lower-value products. This work demonstrates improvements that will increase the mechanical recyclability of polymer waste by introducing accessible functionality to degraded polymers through mechanoradical capture. Trithiocarbonate (TTC) chain transfer agents (CTAs), typically used in reversible addition fragmentation chain transfer (RAFT) polymerizations, have the unique ability to stabilize and capture radicals. Thus, introducing these small molecules during the mechanical recycling process captures the mechanoradicals formed, effectively functionalizing the waste polymers. These functionalized polymers are then employed as macroinitiators for controlled polymerization. In addition, TTC functionalities are used as labile groups that allow for depolymerization to monomer at more accessible temperatures. This novel method generates both higher molecular weight materials akin to virgin polymers and produces monomers that can be repolymerized, offering a promising path toward a circular plastic economy.