齐民
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发表时间:2007-01-01
发表刊物:高分子材料科学与工程
所属单位:化工学院
期号:2
页面范围:92-95
ISSN号:1000-7555
摘要:Poly(L-lactide) (PLLA) was synthesized by ring-opening polymerization of L-lac-tide using cyclic tin alkoxide compound as initiator. Effects of initiator concentration, polymerization temperature and time on the polymers molecular weight were investigated. The experimental results show that high molecular weight PLLA can be obtained by control of the polymerization conditions. The microstructure and stereosequences of PLLA were characterized by 1H-, 13C-NMR. The analysis results verified that ring-opening polymerization of L-lactide initiated with cyclic tin alkoxide may proceed through 'coordinative-insertion' mechanism based on the acyl-oxygen cleavage of L-lactide ring, and the propagation process was proposed. The synthetic PLLA exhibited a high crystallinity of around 40%-50% and no glass transition temperature observed from DSC curves. The thermogravimetry analysis illustrated that the thermal decomposition temperature of PLLA is around 300°C. The tensile properties of polymer films prepared by solution coating were also measured.
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