Living Anionic Polymerization of 4-(α-Alkylvinyl)styrene Derivatives
Living Anionic Polymerization of 4-(α-Alkylvinyl)styrene Derivatives
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DOI：
10.1007/s00706-006-0493-1
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发表时间：
2006-07
期刊：
影响因子：
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通讯作者：
A. Hirao;Takahiro Imai;Kenji Watanabe;M. Hayashi;K. Sugiyama
中科院分区：
文献类型：
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作者：
A. Hirao;Takahiro Imai;Kenji Watanabe;M. Hayashi;K. Sugiyama
以低聚（α-甲基苯乙烯）锂和叔丁醇钾为引发剂，在thfat - 78℃条件下进行了四种α-烷基乙烯基双官能化苯乙烯衍生物的阴离子聚合。本文使用的四种单体是4-异丙基苯乙烯(4)、3-异丙基苯乙烯(5)、2-异丙基苯乙烯(6)和4-（α-异丙基乙烯）苯乙烯(7)。结果表明，在这种聚合条件下，4和7的乙烯基都被选择性聚合，而异丙烯和α-异丙基乙烯基保持完整，形成稳定的活性阴离子聚合物。正如预期的那样，所得到的聚合物具有精确控制的链长和狭窄的分子量分布。更重要的是，它们还在每个单体单元中具有垂坠的异丙烯和α-异丙基，可以进一步修饰。另一方面，阴离子聚合或多或少伴随着不必要的副反应进行，导致链分支，然后是交联。讨论了异丙烯对聚合反应的位置影响及可能产生副反应的原因。
The anionic polymerization of four bis-functionalized styrene derivatives with α-alkylvinyl groups have been carried out inTHFat −78°C with the initiator prepared from oligo(α-methylstyryl)lithium and potassiumtert-butoxide. The four monomers herein used are 4-isopropenylstyrene (4), 3-isopropenylstyrene (5), 2-isopropenylstyrene (6), and 4-(α-isopropylvinyl)styrene (7). It was found that under such polymerization conditions, the vinyl groups of both4and7are selectively polymerized and the isopropenyl and α-isopropylvinyl groups remain completely intact to afford stable living anionic polymers. As expected, the resulting polymers possessed precisely controlled chain lengths and narrow molecular weight distributions. More importantly, they also possessed the pendant isopropenyl and α-isopropylvinyl group in each monomer unit possible for further modification. On the other hand, the anionic polymerization of either5or6proceeded more or less along with the unwanted side reactions leading to chain-branching, followed by cross-linking. The positional effect of isopropenyl group on the polymerization and the cause of possible side reactions were discussed.