Base-Mediated Degradation of Carbon–Carbon Main Chain Polymers Bearing Alkoxycarbonylmethylene Repeating Units

The base-mediated degradation behavior of carbon–carbon (C–C) main chain polymers containing alkoxycarbonylmethylene (ACM) repeating units is described. By the reaction with potassium tert-butoxide (t-BuOK, 0.1 equiv with respect to the ACM repeating unit), poly(alkoxycarbonylmethylene)s (PACMs), which were prepared by Pd-initiated C1 polymerization of alkyl diazoacetates, were found to be effectively degraded into oligomers via abstraction of main chain methine protons followed by retro-Michael addition from the generated enolate species. In addition, polystyrene (PSt) and poly(methyl methacrylate) (PMMA)-based C–C main chain polymers having ACM repeating units, which were synthesized by radical copolymerization of styrene or methyl methacrylate with dialkyl fumarate (DRF) or alkyl acrylate, were also found to be degraded by the reaction with t-BuOK. Some base-degradable ACM-containing copolymers exhibited improved thermophysical properties compared to the corresponding vinyl homopolymers (PSt and PMMA).