Depolymerization of End-of-Life Poly(bisphenol A carbonate) via 4-Dimethylaminopyridine-Catalyzed Methanolysis

Abstract

The chemical recycling, a sequence of depolymerization and polymerization reactions, of end-of-life plastics/polymers can contribute to a sustainable, resource-conserving and environmental-benign society. In this regard, we have set up a protocol for the depolymerization of end-of-life poly(bisphenol A carbonate). In more detail, applying a combination of methanol and catalytic amounts of 4-dimethylaminopyridine (DMAP) end-of-life poly(bisphenol A carbonate) was depolymerized to bisphenol A and dimethyl carbonate. With the aid of microwave heating an excellent rate of depolymerization ( > 99%) within short reaction times (5 min) and turnover frequencies up to 1164 h−1 were achieved. Moreover, it was demonstrated that phenolysis can be applied under optimized reaction conditions resulting in the formation of the mixture bisphenol A and diphenyl carbonate, which can be used for the synthesis of new poly(bisphenol A carbonate). In consequence a closed cycle for poly(bisphenol A carbonate) is feasible.