Preparation and sustainable chemical recycling of green polyesters using enzyme catalysts

Abstract

Environmentally benign processes for polymer synthesis are needed in order to establish green and sustainable polymer chemistry. From the standpoint of saving natural resources and avoiding carbon dioxide emission, the use of renewable or biomass resources is essential for the production of such polymers. The application of enzymatic reactions for the production of green polymers may act as a key role for environmentally benign processes in the next generation. Furthermore, enzymes act effectively as catalysts for the chemical recycling of the polymers. This review focuses on enzymatic processes for polyester synthesis and chemical recycling of bio-based diol-diacid type polymers, poly (butylene succinate) and poly (butylene adipate), and hydroxy-acid type polymers, poly(ricinoleic acid) and poly(12-hydroxystearic acid). High-molecular-weight diol-diacid type polyesters are produced via the ring-opening polymerization of cyclic oligomers using lipase. The produced diol-diacid type polyesters are readily depolymerized by lipases foaming repolymerizable cyclic oligomers for chemical recycling. The sustainable chemical recycling of these polymers and polymer blends using an enzyme is also discussed.