Cationic polymerization with p-substituted benzyl p-hydroxyphenyl methyl sulfonium salts: Effect of substituents and mechanistic aspects of initiation reaction
Cationic polymerization with p-substituted benzyl p-hydroxyphenyl methyl sulfonium salts: Effect of substituents and mechanistic aspects of initiation reaction
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对取代苄基对羟苯基甲基锍盐的阳离子聚合：取代基的影响和引发反应的机理
DOI：
10.1002/pola.1993.080310424
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
T. Endo
中科院分区：
文献类型：
--
作者：
Fumio Hamazu;Sumio Akashi;T. Koizumi;T. Takata;T. Endo
合成了一系列对位取代苄基对羟基苯基甲基锍盐（2），并评价了它们在缩水甘油苯基醚（PGE）本体聚合中的引发活性。活性顺序为2b（X = CH_3）> 2a（X = H）> 2c（X = Cl）> 2d（X = NO_2），表明给电子基团的引入提高了活性。在Hammett图中，聚合速率比的对数（logkx/kH）与σ+ρ的相关性比与σp的相关性好，ρ+值为负（-1.18）。2a与苄基硫醚反应主要生成二苄基硫醚和对羟基苯甲基硫醚。所得结果似乎表明，芳基的OH基团不产生质子作为聚合的引发剂，而苄基引起聚合，其由CS键断裂形成的相应苄基阳离子引发。© 1993约翰威利父子公司。
Various p-substituted benzyl p-hydroxyphenyl methyl sulfonium salts (2) were synthesized and their initiator activities were evaluated in bulk polymerization of glycidyl phenyl ether (PGE). The order of the activity was found to be 2b (X = CH3) > 2a (X = H) ≈ 2c (X = Cl) > 2d (X = NO2), indicating that the introduction of an electron-donating group enhanced the activity. In Hammett's plots, the logarithm of the ratio of the polymerization rates (log kx/kH) was correlated with σ+ρ better than with σp and a negative ρ+ value (-1.18) was obtained. Reaction of 2a with benzyl mercaptan mainly gave dibenzyl sulfide and p-hydroxyphenyl methyl sulfide. The obtained results seemed to demonstrate that the OH group of the aryl group yielded no proton as initiator for the polymerization, whereas the benzyl group caused the polymerization, which was initiated by the corresponding benzyl cation formed by CS bond cleavage. © 1993 John Wiley & Sons, Inc.