Addition copolymers of lactide and glycolide and method of preparation

摘要

Relatively high molecular weight, fiber-forming, crystalline copolymers of lactide and glycolide are prepared in a two-stage polymerization process. In the first stage there is prepared a random copolymer of a major proportion of an optically active lactide with a minor proportion of glycolide or d,l-lactide. In the second stage, a major amount of glycolide and a minor amount of lactide monomers are admixed with the copolymer of the first stage and the polymerization resumed until there is obtained a high molecular weight addition copolymer of lactide and glycolide containing from about 50 to 75 wt percent of units derived from glycolide. The polymer is fiber-forming and useful in the preparation of absorbable surgical sutures.