A biodegradable triblock copolymer comprising: an A-B-A' structure wherein the A and A' blocks each include polylactide, the B block includes from about 55 to about 100 mole percent of polytrimethylene carbonate and 0 to about 45 mole percent polylactide, and the biodegradable triblock copolymer overall includes from about 15 to about 25 mole percent of the polytrimethylene carbonate and from about 75 to about 85 mole percent of the polylactide. Also provided are compositions and implantable medical devices made therefrom.
