Anionic Polymerization of Triphenylmethyl Methacrylate
Anionic Polymerization of Triphenylmethyl Methacrylate
复制标题
甲基丙烯酸三苯甲酯的阴离子聚合
DOI：
10.1021/bk-1981-0166.ch023
复制
发表时间：
1981
期刊：
影响因子：
--
通讯作者：
H. Yuki
中科院分区：
文献类型：
--
作者：
Y. Okamoto;K. Ohta;K. Hatada;H. Yuki
各种甲基丙烯酸酯的立体定向聚合已被广泛研究（1）。其中，甲基丙烯酸三苯甲酯（TrMA）是最令人感兴趣的单体之一，并带来了一些不寻常的结果如下：该单体不仅在甲苯中，而且在四氢呋喃（THF）中与丁基锂（BuLi）形成高度全同立构聚合物（2，3），甚至与自由基引发剂一起，它也产生了富含全同立构规整度的聚合物（2，3，4，5）。TrMA的这种独特性质归因于庞大的三苯基甲基。大酯基也极大地影响其与其他甲基丙烯酸酯（例如甲基丙烯酸甲酯（MMA）或甲基丙烯酸α-甲基苄酯（MBMA）与BuLi（6，7，8））的共聚反应性。（S）-MBMA和TrMA的一些共聚物显示出大的正旋光度，其与（S）-MBMA的均聚物的旋光度符号相反。这种正旋转归因于TrMA单元的全同立构序列，其具有以单螺旋方向螺旋的螺旋构象（9，10，
Stereospecific polymerization of various methacrylates has been extensively studied (1). Among many, triphenylmethyl methacrylate (TrMA) is one of the most interesting monomers and brings about some unusual results as follows: This monomer forms only highly isotactic polymers with butyllithium (BuLi) not only in toluene but in tetrahydrofuran (THF) (2,3), and even with radical initiator it gives a polymer rich in isotacticity (2,3,4,5). This unique nature of TrMA has been ascribed to the bulky triphenylmethyl group. The large ester group also affects greatly its reactivity in the copolymerization with other methacrylates, such as methyl methacrylate (MMA) or α-methylbenzyl methacrylate (MBMA) with BuLi (6,7,8). Some of the copolymers of (S)-MBMA and TrMA shows large positive optical rotations, which are opposite in sign to the rotation of the homopolymer of (S)-MBMA. This positive rotation is attributed to the isotactic sequence of TrMA units which has helical conformation spiraled in single screw sense (9,10,