α,ω-二羧基-甲基丙烯酸丁酯低聚物的合成及MS分析

Synthesis and MS Characterization of α,ω-Dicarboxyl Terminated Oligo(butyl Methacrylate)

利用传统自由基聚合法 ,在四氢呋喃溶液中自由基引发聚合甲基丙烯酸丁酯单体而得到ω 羧基 -甲基丙烯酸丁酯低聚物 (CTBMA) (分子量在 15 0 0左右 ) ;利用CTBMA末端酯基的反应特性 ,在二氧六环 /水 /KOH混合溶液中皂化CTBMA ,使之转化为α ,ω 羧基甲基丙烯酸丁酯低聚物 (di CTBMA) ;研究了溶剂的类别、反应时间等反应条件对皂化产物结构的影响 ;利用MALDI TOF MS及LSIMS对皂化各阶段产物进行了分析监测 .实验表明 ,在适当的皂化条件下 ,CTBMA皂化时主要为末端酯基转化为羧基 ,相应得到的产物di CTMBA具有很好的结构特性 ,其官能团度 (functionality)接近 2 .

A novel method combining a conventional free radical solution polymerization with a chemical saponification was used to synthesize α,ω dicarboxyl terminated oligo(butyl methacrylate)s (di CTBMA) with molecular weight below 1500. Here, ω carboxyl terminated oligo(butyl methacrylate)s (CTBMA) were firstly synthesized by the free radical polymerization in THF, where 4,4′ azobis(4 cyanovaleric acid) was used as initiator, thioglycolic acid as chain transfer agent, then CTBMA were transformed into di CTBMA via saponifying CTBMA in dioxane/H 2O/KOH solution. The influences of important reaction parameters, such as the type of organic solvent, react time on the structures of the saponified substances were monitored by determination of functionality f via acid base titration, MALDI TOF MS and LSIMS analysis. It shows that di CTBMA with the functionality of about 2 could be obtained under a certain reaction parameter.