Control of polymer topology through late-transition-metal catalysis
Control of polymer topology through late-transition-metal catalysis
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DOI：
10.1002/pola.10969
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发表时间：
2003-11-15
影响因子：
--
通讯作者：
Guan, ZB
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文献类型：
--
作者：
Guan, ZB
本文综述了近年来后过渡金属催化剂在聚合物拓扑结构控制中的应用。通过对后过渡金属催化剂的合理选择和设计，可以成功地合成出具有多种拓扑结构的聚合物，包括线型、短支链、超支化、树枝状和环状拓扑结构。催化剂方法的一个显著优点是具有复杂拓扑结构的聚合物可以从简单的商业单体一锅制备。催化剂方法相对于其他方法的根本区别在于聚合物拓扑结构由催化剂而不是单体结构控制。在我们自己的实验室中，我们已经成功地使用了两种策略来控制聚合物的拓扑结构与后过渡金属催化剂。在第一种策略中，超支化聚合物是由二乙烯基单体的直接自由基聚合制备的，通过用钴链转移催化剂控制链转移和链增长之间的竞争。在第二种策略中，聚乙烯拓扑结构是成功地控制的传播和链行走与BrookhartPd-II-α-bisimine催化剂之间的竞争的调节。(C)2003 Wiley Periodicals，Inc.
In this article, recent examples are reviewed of late-transition-metal catalysis applied to polymer topology control. By the judicious selection or design of late-transition-metal catalysts, polymers with a broad range of topologies, including linear, short-chain-branched, hyperbranched, dendritic, and cyclic topologies, have been successfully synthesized. A distinctive advantage of the catalyst approach is that polymers with complex topologies can be prepared in one pot from simple commercial monomers. A fundamental difference of the catalyst approach with respect to other approaches is that the polymer topology is controlled by the catalysts instead of the monomer structure. In our own laboratory, we have successfully used two strategies to control the polymer topology with late-transition-metal catalysts. In the first strategy, hyperbranched polymers are prepared by the direct free-radical polymerization of divinyl monomers through control of the competition between propagation and chain transfer with a cobalt chain-transfer catalyst. In the second strategy, polyethylene topology is successfully controlled by the regulation of the competition between propagation and chain walking with the Brookhart Pd-II-alpha-bisimine catalyst. (C) 2003 Wiley Periodicals, Inc.