Synthesis of alternating copolymers of N-substituted maleimides with styrene via atom transfer radical polymerization
Synthesis of alternating copolymers of N-substituted maleimides with styrene via atom transfer radical polymerization
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DOI：
10.1021/ma991047b
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发表时间：
2000-01-25
期刊：
影响因子：
5.5
通讯作者：
Li, FM
中科院分区：
文献类型：
--
作者：
Chen, GQ;Wu, ZQ;Li, FM
导论.原子转移自由基聚合（ATRP）作为一种新型的精密聚合方法，由于其能有效控制聚合物的分子量分布，近年来受到了广泛的关注。ATRP体系的优点是它可以通过普通的自由基聚合过程进行。一般的ATRP催化剂由作为引发剂的简单烷基卤化物和作为催化剂的铜（I）-联吡啶络合物组成。ATRP的反应机理是在过渡金属配合物的催化下，碳-卤键发生可逆的均裂。许多乙烯基单体被成功地证明是可用于制备传统的均聚物，无规共聚物，嵌段/接枝共聚物，和梯度共聚物。此外，ATRP还显示了其在合成各种新的明确的大分子结构，如梳状，3星星，树枝状大分子的潜力。4然而，关于通过ATRP合成定义明确的交替共聚物的报道很少。众所周知，交替共聚物可以通过形成电荷转移络合物（CTC）通过富电子单体和缺电子单体的共聚容易地获得。广泛研究的体系之一是马来酸酐（MAn）和苯乙烯（St）。聚合可以通过自由基引发剂如AIBN或通过UV光照射引发，但聚合过程是不可控的。因此，是否通过ATRP发生形成单体对的CTC的可控交替共聚是值得关注的。Matyjasewski等人报道了供体单体如异丁烯和乙烯基异丁基醚与受体单体如丙烯酸丁酯通过ATRP的共聚，表明聚合是可控的。8本文报道了苯乙烯（St）与N-取代马来酰亚胺（N-（2-乙酰氧基乙基）马来酰亚胺（AEMI）和N-苯基马来酰亚胺（PhMI））的ATRP共聚反应，旨在评价CTC形成单体对是否通过可控/“活性”共聚反应进行，以及所得共聚物是否具有主要的交替结构。
Introduction. As a novel precision polymerization, atom transfer radical polymerization (ATRP) has received rapidly increased interest recently, since it furnishes control over the resulting polymers, which possess narrower molecular weight distributions. 1, 2 The merit of the ATRP system is that it can be performed by an ordinary radical polymerization procedure. A general ATRP catalyst is composed of a simple alkyl halide as an initiator and a copper (I)-bipyridine complex as a catalyst. The mechanism of ATRP is shown to be a reversible homolytic cleavage of a carbon-halogen bond catalyzed by a transition metal in the form of a complex. Many vinyl monomers were successfully demonstrated by ATRP to be usable for the preparation of traditional homopolymers, random copolymers, block/graft copolymers, and gradient copolymers. In addition, ATRP also shows its potential in the synthesis of a variety of new well-defined macromolecular architectures such as comb, 3 star, and dendritic macromolecules. 4 However, reports on the synthesis of welldefined alternating copolymers via ATRP are scarce. 5 It is well-known that an alternating copolymer can be easily obtained by the copolymerization of an electronrich monomer and an electron-deficient monomer through the formation of charge transfer complexes (CTCs). One of the extensively studied systems is maleic anhydride (MAn) and styrene (St). The polymerization can be initiated by radical initiators such as AIBN or by UV light irradiation, but the polymerization process is uncontrollable. 6, 7 Therefore, whether a controllable alternating copolymerization of CTCs forming a monomer pair takes place by ATRP is of concern. Matyjasewski et al. reported on the copolymerization of donor monomers such as isobutene and vinyl isobutyl ether with acceptor monomers such as butyl acrylate via ATRP, showing that the polymerization was controllable. 8 In this article, the copolymerization of styrene (St) with N-substituted maleimides, ie, N-(2-acetoxyethyl) maleimide (AEMI) and N-phenylmaleimide (PhMI), by ATRP have been reported aiming to evaluate whether the CTCs forming a monomer pair takes place by controllable/“living” copolymerization and whether the resulting copolymers possess the predominantly alternating structure.