Selective Electrochemical Modification and Degradation of Polymers

Presented within is a selective electrochemical decarboxylative route to synthesize olefin-acrylate copolymers by post-polymerization modification, which are difficult to synthesize by direct polymerization. In addition, the electrochemical decarboxylative methodology provides a targeted approach to the degradation of polymethacrylates. This approach provides an attractive route to the modification and chemical recyclability of polymers.

Abstract

We demonstrate that electrochemical-induced decarboxylation enables reliable post-polymerization modification and degradation of polymers. Polymers containing N-(acryloxy)phthalimides were subjected to electrochemical decarboxylation under mild conditions, which led to the formation of transient alkyl radicals. By installing these redox-active units, we systematically modified the pendent groups and chain ends of polyacrylates. This approach enabled the production of poly(ethylene-co-methyl acrylate) and poly(propylene-co-methyl acrylate) copolymers, which are difficult to synthesize by direct polymerization. Spectroscopic and chromatographic techniques reveal these transformations are near-quantitative on several polymer systems. Electrochemical decarboxylation also enables the degradation of all-methacrylate poly(N-(methacryloxy)phthalimide-co-methyl methacrylate) copolymers with a degradation efficiency of >95 %. Chain cleavage is achieved through the decarboxylation of the N-hydroxyphthalimide ester and subsequent β-scission of the backbone radical. Electrochemistry is thus shown to be a powerful tool in selective polymer transformations and controlled macromolecular degradation.

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