Novel lipase-catalyzed ring-opening copolymerization of lactide and trimethylene carbonate forming poly(ester carbonate)s

Poly(lactide-co-trimethylene carbonate)s were prepared by the lipase-catalyzed ring-opening copolymerization of lactide and trimethylene carbonate having carbonate content from 0 to 100%. Their thermal properties and enzymatic degradability were measured. The L,L-, D,D- and D,L-lactides were copolymerized with trimethylene carbonate by porcine pancreatic lipase to produce random copolymers having molecular weights of up to 21 000. The glass transition temperature (T-g) of the copolymer was dependent on the carbonate content and the T-g values linearly decreased from 35 degrees C (polylactide) to -8 degrees C [poly(trimethylene carbonate)]. Among the lipases tested, the porcine pancreatic lipase and proteinase K showed biodegradability towards poly(ester-carbonate)s. (C) 1999 Elsevier Science B.V. All rights reserved.