多臂星形聚乙二醇的合成

聚乙二醇(PEG)经与丁二酸酐发生酯化后,在两末端引入羧基,再与氯化亚砜反应得到聚乙二醇二酰氯,此产物再分别与丙三醇、季戊四醇或D-山梨醇等多元醇反应,可分别得到三臂、四臂和六臂星形PEG。用傅里叶变换红外光谱和核磁共振氢谱等对各产物进行了表征,端基分析法得到三臂、四臂和六臂PEG的数均分子量平均值分别为3 794,4 738,6 432,表明采用上述合成路线可成功得到末端为羧基的多臂星形PEG。

Preparation of multi-arm star polyethylene glycol

Two carboxyl groups were introduced at the chain end of esterification product derived from the reaction between PEG and succinic anhydride and then,the product reacted with thionyl chloride to prepare ClOC-PEG-COCl.Furthermore,the resultant intermediate reacted with polyols,such as glycerol,pentaerythritol or D-sorbitol,to make three-,four-,or six-arm PEGs,respectively.The ultimate products were characterized by Fourier transform infrared spectroscopy(FTIR) and hydrogen nuclear magnetic resonance(1H-NMR).The number average molecular mass of three-,four-,or six-arm PEGs was 3 794,4 738,and 6 432,respectively,as measured with the end group titration method.The results indicate that the aforementioned synthesis route is a feasible method to prepare multi-arm star PEG with carboxyl end group.