Precise Syntheses of Alternating Cyclocopolymers via Radical Copolymerizations of Divinyl Ether with N-Substituted Maleimides
Precise Syntheses of Alternating Cyclocopolymers via Radical Copolymerizations of Divinyl Ether with N-Substituted Maleimides
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DOI：
10.1021/acs.macromol.2c00172
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发表时间：
2022-03
期刊：
影响因子：
5.5
通讯作者：
Hiroyuki Kubota;M. Ouchi
中科院分区：
文献类型：
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作者：
Hiroyuki Kubota;M. Ouchi
以N-取代马来酰亚胺（MIs）为单体，通过自由基共聚合反应合成了具有稠环结构的交替环共聚物。两种单体中C=C键的消耗行为和接近于零的假单体竞聚率的值支持DVE双键之一、MI、DVE的另一个双键和MI的顺序的交替增长，以提供拓扑独特的共聚物。通过RAFT过程控制环聚合，因此，通过顺序添加MI实现了在MI单元上携带不同侧基的多嵌段交替环聚合物的一锅法合成。该系列交替的环状共聚物表现出高的热稳定性和高的玻璃化温度（Tg）。特别地，基于N-乙基MI的环状聚合物的Tg远高于Fox方程的预测值，这可能来自于包括稠环结构的刚性主链。
Alternating cyclocopolymers having a condensed ring structure were synthesized via radical copolymerization of the divinyl ether (DVE) carrying agem-dimethyl group on the spacer withN-substituted maleimides (MIs). The consumption behaviors of the C=C bonds in both monomers and the values of the pseudo-monomer reactivity ratios close to zero supported the alternating propagation in the order of one of the DVE double bonds, MI, another double bond of DVE, and MI, to afford the topologically unique copolymers. The cyclocopolymerization was controlled via the RAFT process, and thus, one-pot synthesis of the multiblock alternating cyclocopolymer carrying different pendant groups on the MI units was achieved via sequential addition of MIs. The series of alternating cyclocopolymers exhibited high thermal stabilities and high glass temperatures (Tgs). In particular,Tgof theN-ethyl MI-based cyclocopolymer was much higher than the predicted value by the Fox equation, which was presumably derived from the rigid backbone including the condensed ring structure.