Preparation and properties of poly(L-lactide)-block-poly(trimethylene carbonate) as biodegradable thermoplastic elastomer

Biodegradable ABA triblock copolymers of L-lactide and trimethylene carbonate with given compositions were prepared and chain-extended to produce high molecular weight polymer. The polymers were semicrystalline, and exhibited well microphase-segregated morphology with one crystalline poly(L-lactide) (PLLA) and the other soft and amorphous poly(trimethylene carbonate) (PTMC) block segments. The polymers could be cast into flexible and tough film, reversibly stretchable with elongation up to about 300%. This material may provide a novel thermoplastic elastomer possessing desirable properties including biodegradability, biocompatibility and good mechanical properties including two-phase morphology. Also a preliminary result on the hydrolytic degradation behavior was discussed.