摘要
以L-乳酸为原料,季戊四醇为支化剂,采用SnCl2·2H2O/TSA复合催化剂合成了星形支化聚L-乳酸,并采用DSC、偏光显微镜研究了星形聚L-乳酸的结晶和熔融行为,探讨了星形聚乳酸的热降解性能。DSC研究结果表明,熔融缩聚制备的星形聚L-乳酸在升温过程中基本观察不到冷结晶峰,只出现一个熔融峰。经过等温结晶处理后的星形聚L-乳酸再次升温时出现双熔融峰,其中低熔融峰的峰值温度(Tm(L))与等温结晶温度的对数值成线性增长关系,而高熔融峰的峰值温度(Tm(H))与等温结晶温度基本无关。
Star-shaped poly（L-lactic acid） （PLLA） was synthesized using L-lactic acid as the monomer, pentaerythritol as the branching reagent and SnCl2·2H2O/TSA as the composite catalyst. The crystallization, melting as well as thermal-degradation behaviors of the obtained PLLA were studied using DSC and polarizing microscopy. The results of DSC demonstrated that the cold crystallization peak was hardly observed during the heatingup process of the star-shaped PLLA synthesized by melt polycondensation, only a melting peak showed. However, a double-melting peak was observed on the star-shaped PLLA after the treatment of isothermal crystallization. The temperature of the low melting peak was linearly increasing with the logarithmic value of the isothermal crystallization temperature, while the temperature of the high melting peak showed little correlation with the latter.
出处
《化学与粘合》
CAS
2009年第5期18-20,25,共4页
Chemistry and Adhesion
基金
北京市市管高等学校人才强教计划资助项目
北京市教委科技发展计划资助项目
(编号:KH200810017007)
关键词
聚乳酸
星形聚合物
熔融缩聚
等温结晶
熔融
Poly（L-lactic acid）
star-shaped polymer
melt polycondensation
isothermal crystallization
melting
