Synthesis of poly(D,L-lactic acid-alt-glycolic acid) from D,L-3-methylglycolide

D,L-3-Methylglycolide (MG) was synthesized via two step reactions with a go od yield (42%). It was successfully polymerized in bulk with stannous octoa te as a catalyst; at 110 degreesC. The effects of the polymerization time a nd catalyst concentration on the molecular weight and monomer conversion we re studied. Poly(D,L-lactic acid-co-glycolic acid) (D,L-PLGA50; 50/50 mol/m ol) copolymers were successfully synthesized from the homopolymerization of MG with high polymerization rates and high monomer conversions under moder ate polymerization conditions. H-1 NMR spectroscopy indicated that the bulk ring-opening polymerization of MG conformed to the coordination-insertion mechanism. C-13 NMR spectra of D,L-PLGA50 copolymers obtained under differe nt experimental conditions revealed that the copolymers had alternating str uctures of lactyl and glycolyl. (C) 2000 John Wiley & Sons, Inc.