用变温红外研究聚乳酸嵌段共聚物生成过程中的化学反应

Study on the Reaction between PLLA and PCL Prepolymers by in Situ FTIR

本文采用熔融缩聚法合成一定分子量的聚乳酸(PLA),采用聚己内酯多元醇(PCL)的聚氨酯预聚体进行共聚反应,以制得PLA-PCL嵌段共聚物。采用变温红外研究了PLA预聚体与PCL预聚体的反应活性,并研究了共聚产物的分子量。结果表明,PLA预聚体与PCL预聚体具有很高的反应活性,共聚后PLA的分子量有大幅度提高。

In this paper, PLLA prepolymers were synthesized by melt polycondensation, and then PLLA-PCL were prepared by using the coupling reaction between PLLA prepolymer and PCL prepolymer with -NCO terminals. In situ FTIR was used to characterize the activity of reaction between -NCO groups at the end of PCL and -OH （or -COOH） groups at the end of PLLA, and results showed that the reaction was of high activity. Gel permeation chromatography （GPC） data indicated that the molecular weight of PLLA -PCL multiblock copolymers was higher than that of PLLA prepolymer.