Visible light-induced degradation of acrylate/methacrylate copolymers with comonomer triggers

Abstract

Degradation of mass-manufactured acrylate/methyl acrylate polymers is considered to be a promising path to alleviate the growing and alarming plastic waste issue. However, deconstruction of such stable polymers remains a daunting challenge due to their stable saturated backbone, with previous strategies primarily relying on harsh reaction conditions or cumbersome synthetic polymers that are not suitable for practical implementation and industrialization. Herein, we report a main chain-initiated, visible light-induced degradation methodology under mild conditions, which is applicable to various categories of acrylate or methacrylate copolymers. These acrylate or methacrylate copolymers could be readily prepared by copolymerizing diverse acrylate/methacrylate monomers with low mol% acrylic acid/methacrylic acid (AA/MAA), which could serve as degradable triggers. These triggers consisting of COOH groups could generate –COOCe^IV species by coordinating with a cerium catalyst followed by oxidation in the presence of O₂, thereby initiating the ligand-to-metal charge transfer process and decarboxylation under visible light irradiation to produce alkyl radicals to trigger degradation via backbone scission. More importantly, this efficient degradation could be accomplished regardless of the synthetic routes, pendant groups, chain-end functionalities, molecular weights, topological architectures and concentrations of polymers, rendering this strategy a robust route to degrade diverse acrylate/methacrylate polymers.