Living Cationic Polymerization of Vinyl Ether with Methanol/Metal Chloride Initiating Systems: Relationship between Polymerization Behavior and the Nature of Lewis Acids
Living Cationic Polymerization of Vinyl Ether with Methanol/Metal Chloride Initiating Systems: Relationship between Polymerization Behavior and the Nature of Lewis Acids
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DOI：
10.1021/ma902616j
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发表时间：
2010-02
期刊：
影响因子：
5.5
通讯作者：
Arihiro Kanazawa;S. Kanaoka;S. Aoshima
中科院分区：
文献类型：
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作者：
Arihiro Kanazawa;S. Kanaoka;S. Aoshima
用甲醇/金属氯化物引发体系代替常规使用的VE-质子酸加合物引发剂，研究了乙烯基醚（VE）的阳离子聚合。使用MoCl 5（一种高度亲氧的金属卤化物），在乙酸乙酯存在下，异丁基VE（IBVE）使用甲醇的聚合以活性方式进行，尽管该反应不受IBVE−HCl加合物的控制。此外，在甲醇引发的聚合中，所用的刘易斯酸根据聚合行为可主要分为三类：产生长寿命物种的那些（例如，MoCl 5、NbCl 5和ZrCl 4），诱导不受控制的聚合的那些（例如，GaCl 3和FeCl 3），或根本不显示活性的那些（例如，ZnCl 2和InCl 3）。产物聚合物的基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS）谱和反应混合物的直接1H NMR分析表明，可控聚合阶段是一种有效的聚合方法。
Cationic polymerization of vinyl ether (VE) was examined with methanol/metal chloride initiating systems instead of those with the conventionally used VE−protonic acid adduct initiators. With MoCl5, a highly oxophilic metal halide, the polymerization of isobutyl VE (IBVE) using methanol proceeded in a living fashion in the presence of ethyl acetate, although the reaction was not controlled in conjunction with IBVE−HCl adduct. Furthermore, in the methanol-initiated polymerization, the Lewis acids used could be classified mainly into three categories in terms of polymerization behavior: those producing long-lived species (e.g., MoCl5, NbCl5, and ZrCl4), those inducing uncontrolled polymerization (e.g., GaCl3 and FeCl3), or those showing no activity at all (e.g., ZnCl2 and InCl3). The matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI−TOF−MS) spectra of the product polymers and the direct 1H NMR analysis of the reaction mixtures revealed that the controlled polymerization sta...