聚乙二醇与二氯亚砜反应合成氯代聚乙二醇过程研究

Synthesis of Chloro-Terminated Polyethylene Glycol via Reaction of Polyethylene Glycol and Thionyl Chloride

以吡啶为缚酸剂,二氯亚砜为氯化试剂对不同聚合度的聚乙二醇(PEG)进行端羟基取代,研究了反应过程中缚酸剂用量、反应温度、时间和聚乙二醇聚合度等条件对PEG转化率和氯代聚乙二醇(PEGCl)收率的影响;采用羟值测定、傅里叶变换红外光谱、核磁共振氢谱等技术对PEGCl的结构进行了分析。结果表明,在二氯亚砜、吡啶和聚乙二醇摩尔比为6:6:1时,PEG基本全部转化;在反应温度35~45℃,PEGCl的收率较高;随着反应时间延长,PEG转化率逐渐提高,但若反应时间过长则生成较多副产物,使PEGCl收率降低;当聚乙二醇聚合度较高时,氯化反应速率更快。经分析红外光谱和核磁共振氢谱表征可知,所得产物纯度较高。

Chloro-terminated polyethylene glycol （PEGC1） was synthesized through chlorination of hydroxyls of polyethylene glycol （PEG） using thionyl chloride and pyridine as the chlorinating agent and acid-accepter, respectively. Effects of pyridine amount, reaction temperature, reaction time and polymerization degree of PEG on PEG conversion and PEGC1 yield were investigated. PEGC1 was characterized by FTIR, 1H-NMR and hydroxyl number measurements. The result shows that PEG is completely converted when the molar feeding ratio of thionyl chloride, pyridine and PEG polyethylene glycol is 6：6：1. The suitable reaction temperatures range from 35 ℃ to 45 ℃, which guarantees high yield of PEGC1. PEG conversion increases when the reaction time increases, and the reaction time should not be over extended to avoid formation of too many by-products. PEG with higher molecular weights shows higher reaction rates. Moreover, FTIR and 1H-NMR spectra of PEGCI indicate high purity of the products.