Molten ring-open copolymerization of L-lactide and cyclic trimethylene carbonate

Abstract

The biodegradable poly(L-lactide-co-trimethylene carbonate) [poly(LLA-co-TMC)] was synthesized by molten ring-open copolymerization and the structure and properties of the copolymer were investigated by GPC, NMR, FTIR, DSC, and Instron testing. The copolymer with a higher LLA content had a higher initial molecular weight (Mn), but a lower final Mn. In contrast, the copolymer with a higher TMC content had a lower initial Mn, but its Mn increased with increasing reaction time and TMC content. The glass transition temperature (Tg), the melting temperature (Tm) and the crystallinity of the copolymer decreased with increasing TMC content. The elongation of the copolymer significantly increased with increasing TMC content while the toughness passed through a maximum. © 1998 John Wiley & Sons, Inc.