Copolymerization of glycolide and trimethylene carbonate

The bulk ring‐opening copolymerization of glycolide with trimethylene carbonate was performed under different conditions. The influence of the composition, temperature, reaction time, and catalyst on the chain microstructure was studied by means of ¹H and ¹³C NMR spectroscopy. The final microstructure was found to be highly dependent on the transesterification reactions. The thermal behavior was sensitive to the composition and to the length of the glycolyl microblocks. Differential scanning calorimetry and X‐ray diffraction demonstrated that glycolyl‐rich sequences could give rise to a single crystalline phase, whereas trimethylene carbonyl units were incorporated into the amorphous phase. The synthesis of copolymers from the melt‐state transesterification of polyglycolide and poly(trimethylene carbonate) homopolymer mixtures was also studied. The hydrolytic degradation rate of the copolymers was found to depend on the microstructure and in general was enhanced with the degree of randomness. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 993–1013, 2006