2,4-甲苯二异氰酸酯扩链合成聚乳酸的研究

Study on the Synthesis of Polylactic Acid through 2,4-Toluylene Diisocyanate Chain Extension

采用直接熔融缩聚法先合成相对低分子量的聚乳酸,再以2,4-甲苯二异氰酸酯(TDI)作为扩链剂进行扩链反应。研究了反应时间、温度及扩链剂用量对聚乳酸分子量的影响,并采用IR、DSC及GPC对产物进行表征。实验结果表明:在170℃、0.09MPa下以质量分数10%的TDI作为扩链剂进行扩链反应1.5h,产物分子量提高3.72倍。

Polylactic acid with low molecular weight was prepared by the direct melt polycondensation, then 2, 4-toluylene diisocyanate （TDI） was used as chain extender to improve the molecular weight. The influence of reaction temperature, time and the amounts of TDI on molecular weight were studied. The products were characterized by IR, DSC and GPC. The results indicates that the molecular weight of chain extension products could be 3.72 times higher than before under the condition of 170℃, 0. 09MPa, 10% TDI as chain extender for 1.5h.