Enzymatic synthesis of polyesters via ring-opening polymerization

An enzyme can act as a powerful catalyst for the production and chemical recycling of green and sustainable polymers via a ring-opening polymerization. Also, enzymes will provide versatile synthetic tools for regio- and enantioselective polymerizations. In this article, lipase-catalyzed ring-opening polymerization and copolymerization of small-sized four-membered lactones to macrolides and cyclic oligomers having a molecular weight of a few hundred into high-molecular-weight polyesters, ring-opening polymerization of substituted/unsubstituted cyclic carbonates and cyclic phosphates into polycarbonates and polyphosphates, and the mechanism of lipase-catalyzed ring-opening polymerization of lactones and cyclic carbonates are reviewed. Also degradative transformation of polyesters and polycarbonates into the corresponding cyclic oligomers as repetitive chemical recycling and trends for enzymatic ring-opening polymerization and degradation are described.