Abstract: The synthesis and thermal stability of poly(L-lactide) were investigated. The key factors affecting the polymer intrinsic viscosity were found to be monomer recrystallization times, stannous octoate concentration and polymerization time. The thermal stabilizing agent did not significantly affect the polymer molecular weight. The polymer with a viscosity average molecular weight beyond 200000 was fairly reproducible by optimizing the polymerization conditions. It was found that poly(L-lactide)is thermally unstable above its melting temperature. The thermal stabilizing agent, ULTRANOX 626A, appeared to be able to reduce the extent of the thermal degradation of the polymer.

Key words: poly(L-lactide), biodegradable, intrinsic viscosity, thermal stability

摘要： 对聚丙交酯的合成和热稳定性进行了研究。单体重结晶次数、辛酸亚锡浓度、聚合时间等条件均是影响聚合物特性粘数的重要因素。热稳定剂对聚丙交酯的分子量几乎没有影响。优化聚合条件可以获得粘均分子量大于200000的聚丙交酯材料，聚合结果具有良好的重复性。实验表明在高于聚合物熔点温度以上，聚丙交酯表现出热不稳定性。热稳定剂ULTRONOX 626A能够有效降低聚丙交酯的热降解幅度。

关键词: 聚L-丙交酯, 可生物降解, 特性粘数, 热稳定性