衰减链转移自由基聚合醋酸乙烯酯  

Degenerative Chain Transfer Radical Polymerization of Vinyl Acetate

作　　者：许文静[1] 张颖[1] 张可达[1] 

机构地区：[1]苏州大学化学化工学院,江苏苏州215123

出　　处：《石油化工》2007年第6期575-578,共4页Petrochemical Technology

基　　金：国家自然科学基金项目(2047404220574049)

摘　　要：以偶氮二异丁腈为引发剂,在醋酸乙烯酯(VAc)的普通自由基聚合反应体系中加入少量碘,原位生成了碘化物α-碘代异丁腈,该碘化物在聚合过程中起可逆的链转移剂的作用,合成了含碘端基的聚醋酸乙烯酯(PVAc-I);考察了反应温度、原料配比对聚合反应的影响。实验结果表明,反应温度为75℃较适宜VAc的聚合;在该温度下,VAc通过衰减链转移自由基聚合法可合成相对分子质量可控、相对分子质量分布较窄(Mw/Mn≤1.41)的PVAc-I,并用核磁共振仪对PVAc-I的结构进行了表征。PVAc-I与甲基丙烯酸甲酯的嵌段共聚实验结果表明,PVAc-I末端的碘具有活性,合成的嵌段共聚物聚醋酸乙烯酯-b-甲基丙烯酸甲酯的相对分子质量分布窄(Mw/Mn=1.43)。Iodic - end - group poly （ vinyl acetate） （ PVAc - I） was synthesized from vinyl acetate （VAc） by degenerative chain transfer radical polymerization in presence of iodine with 2.2＇ - azobisisobutyronitrile （AIBN） as initiator. In the polymerization, radicals initiated from AIBN firstly reacted in situ with iodine to produce α -iodoisobutyronitrile （CH3）2（CN）CI, which then acted as chain transfer agent in the polymerization. Effects of reaction temperature and n（VAc） ： n（AIBN） ： n（ 12 ） on the polymerization were investigated. PVAc -I with adjustable relative molecular mass and narrow relative molecular mass distribution（Mw/Mn≤1. 41 ） can be synthesized at 75 ℃. The PVAc -I was characterized by means of ^1H NMR. Iodine at the end of PVAc - I molecule is active, which is proved by block copolymerization of PVAc - I and methyl methacrylate. The block copolymer poly （ vinyl acetate） - b - methyl methacrylate with narrow relative molecular mass distribution （ Mw/Mn = 1.43 ） is obtained.

关 键 词：醋酸乙烯酯 聚醋酸乙烯酯 碘端基的聚醋酸乙烯酯 碘 衰减链转移自由基聚合 链转移剂 

分 类 号：TQ325.5[化学工程—合成树脂塑料工业]