Optically active biodegradable block copolyester and its preparation

摘要

An optically active block copolymer polyester comprising of structural units represented by the following general formulas (I) and (II): (wherein *C stands for an asymmetric carbon atom and m and n each for a natural number in the range of from 300 to 5000) is obtained by subjecting an optically active beta -butyrolactone and lactone compound other than the optically active beta -butyro-lactone to sequential ring-opening copolymerization in the presence of a catalyst. This optically active block copolymer polyester possesses a high molecular weight and a high melting point (not lower than 130 DEG C) and forms a biodegradable and hydrolyzable material of high strength capable of resisting to the impacts of actual use conditions.