SYNTHESIS OF TIDE)-BLOCK-POLYISOBUTYLENE-BLOCK-POLY(L-LACTIDE), A NEWBIODEGRADABLE THERMOPLASTIC ELASTOMER

The anionic ring-opening polymerization of L-lactide was initiated by dipotassium-polyisobutylene-alcoholate telechelic polymer to yield cti de)-block-polyisobutylene-block-poly(L-lactide) triblock copolymer, a partially biodegradable thermoplastic elastomer. The pure triblock cop olymer was obtained by gradient column chromatography on silica gel. T he molar mass and molar mass distribution of the block copolymer was a scertained by SEC and quantitative H-1 NMR spectroscopy. It showed two glass transitions and microphase separation.