COPOLYMER SYNTHESIS OF POLY(L-LACTIDE-B-DMS-L-LACTIDE) VIA THE RING-OPENING POLYMERIZATION OF L-LACTIDE IN THE PRESENCE OF ALPHA,OMEGA-HYDROXYLPROPYL-TERMINATED PDMS MACROINITIATOR

Various amounts of hydroxy terminated PDMS were linked into PLLA chain s via in-situ ring opening polymerization at a very low content of SnO t(2). The H-1 and FTIR spectra provided evidence for the incorporation of the PDMS in the PLLA chains. The molecular weights, T-g, T-m, crys tallinity and the heats of fusion decreased as the feed mole ratio of PDMS/LLA in the block copolymer increased. The molecular weight distri bution broadened as the content of the PDMS increased, due the occurre nce of two initiation and propagation mechanisms. Linking PDMS into th e PLLA chains improved its thermal stability. (C) 1996 John Wiley & So ns, Inc.