溶液共沸法直接合成较高分子量的聚乳酸

Preparation of Poly(lactic acid) by Direct Polycondensation in Azeotropic Solution

采用溶液共沸法直接缩聚制备聚乳酸。探讨了复合催化剂、溶剂用量、反应时间及反应装置对聚乳酸相对分子质量的影响。结果表明:以乳酸质量分数w=0.01的复合催化剂(其中氯化亚锡与对甲苯磺酸质量比为1∶1)为催化剂,溶剂与乳酸的体积比为0.75∶1.00,在氮气氛保护下反应35 h左右,能得到重均分子量为6.6×104的聚乳酸。

Poly （lactic acid） （PLA） was prepared by means of direct polycondensation in azeotropic solution. The effects of the variety and content of catalysts, process, solvent volume percentages and the reaction time on the preparation were studied. The result shows that, in the improved experimental equipment, under the N2 protection for 35 h, and by using the proper complex catalyst and solvent volume ratio,M^-w of PLA can be to 6.6×10^4.