聚乳酸的熔融聚合法的改进研究

Study on improvement of melt polymerization of polylactic acid

采用熔融聚合法合成聚乳酸,对实验条件进行了优化选择。筛选出SnC l2为最适宜催化剂进行熔融聚合。最佳工艺条件为:催化剂用量为0.5%质量分数,反应温度为180℃,反应时间7.5 h,同时利用搅拌与鼓泡真空法使缩聚后期体系粘稠大搅拌脱水困难问题进一步得到解决,使熔融聚合产物的粘均分子量Mη达83483。

This paper reports melt polymerization of polylactic acid （PLA）. The best reaction conditions have been chosen by repcated experiments. SnCl2 was chose as the appropriate catalyst. Thc optimal reaction conditions were found out ,that is O. 5% SnCl2, 180℃ and 7.5 h. Meanwhile the difficulty which is removing water reduced by posterior reaction has been further solved via stir and plumping bladders in the condition of vacuum. The molecular weight Mn of the PLA via melt polymerization can be achieved 83483.