Aromatic Acetals as New Initiators for Cationic Polymerization of Isobutyl Vinyl Ether1
Aromatic Acetals as New Initiators for Cationic Polymerization of Isobutyl Vinyl Ether1
复制标题
芳香族缩醛作为异丁基乙烯基醚阳离子聚合的新型引发剂1
DOI：
10.1021/ma991571i
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发表时间：
2000
期刊：
影响因子：
5.5
通讯作者：
M. Sawamoto
中科院分区：
文献类型：
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作者：
K. Satoh;M. Kamigaito;M. Sawamoto
以取代苯酚[CH3CH(OiBu)OAr；Ar=C6H5，p-CH3OC(O)C6H4，p-CH3C(O)C6H4，p-NO2C6H4，4-NO2-2，6-diC6H5−C6H2，o-CH3C(O)C6H4]为引发剂，与路易斯酸(MtXn)联用，研究了异丁基乙烯基醚的活性阳离子聚合反应。其中大部分是通过在IBVE中加成相应的酚类化合物来定量合成的。当与三氯化铝(AlCl3)偶联时，1得到了具有宽分子量分布(∼)的聚合物，而乙酸乙酯(10%)的加入导致了受控聚合物的形成，其数均相对分子质量(Mn)与单体转化率成正比，但分布相对较窄(Mw/mN MWDS为1.2)。芳香族缩醛与卤化锡(SnX4；X=Cl，Br3)在−为78°C时，甲苯中的中间体含量较高(81%)。
A series of aromatic acetals (1) from substituted phenols [CH3CH(OiBu)OAr; Ar = C6H5, p-CH3OC(O)C6H4, p-CH3C(O)C6H4, p-NO2C6H4, 4-NO2-2,6-di-C6H5−C6H2, o-CH3C(O)C6H4] were employed as new initiators in conjunction with Lewis acids (MtXn) for the living cationic polymerization of isobutyl vinyl ether (IBVE). Most of them were quantitatively synthesized by the addition of the corresponding phenols to IBVE. When coupled with aluminum chloride (AlCl3), 1 gave polymers with broad molecular weight distributions (MWDs), whereas the addition of ethyl acetate (10 vol %) to these systems led to the formation of controlled polymers whose number-average molecular weights (Mn) were directly proportional to monomer conversion, with relatively narrow distributions (Mw/Mn ∼ 1.2). The aromatic acetals in conjunction with tin halides (SnX4; X = Cl, Br) gave relatively high meso contents (81%) in toluene at −78 °C.