Synthesis and Backbone Modification of Sustainable Acrylate Copolymers Promotes Photodegradation

Abstract

Degradable plastics are vital for the shift to a circular materials economy. The insertion of ketones, a known photodegradable functional group, into polymer backbones is one strategy to synthesize thermoplastic polymers with inherent degradability. This strategy is however limited in the literature to metal-mediated methods or those that rely on carbon monoxide monomer. This work develops a metal-free, controlled, light-initiated RAFT polymerization to synthesize copolymers of poly(methyl acrylate) with low amounts of randomly incorporated tert-butyl vinyl ether. This novel polymer microstructure is shown to undergo hydrolysis, affording poly(methyl acrylate-co-hydroxyl). Oxidizing the hydroxyl groups gives rise to the poly(ketone); however, full conversion to ketone was not observed via the oxidation methods tested. However, this work explores two additional degradation pathways starting from poly(MA-co-OH). The hydrolyzed copolymer readily degraded via photooxidative methods, and further work is ongoing to probe proton-coupled electron transfer (PCET) reactivity to cleave the backbone of poly(MA-co-OH). Overall, this light-driven approach offers versatile polymer microstructures that can degrade, thus paving the way for the development of sustainable materials in our economy.