Introduction of Highly Tunable End-Groups in Polyethylene via Chain-Transfer Polymerization using a Cobalt(III) Catalyst
Introduction of Highly Tunable End-Groups in Polyethylene via Chain-Transfer Polymerization using a Cobalt(III) Catalyst
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DOI：
10.1021/acs.organomet.8b00765
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发表时间：
2019-02
期刊：
影响因子：
2.8
通讯作者：
Michael G. Hyatt;Damien Guironnet
中科院分区：
文献类型：
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作者：
Michael G. Hyatt;Damien Guironnet
以硅烷为链转移剂，五甲基亚磷酸钴烷基酯为催化剂，通过乙烯的链转移聚合直接合成了高度可调的末端官能化聚乙烯分子。进行了一系列的聚合和动力学研究的不同的基本步骤中涉及的催化循环，以建立的方法，并获得更深入的了解的反应机理。链转移的速率以及因此聚合物长度可以通过改变硅烷浓度或取代基来独立地调节。链转移方法与基于后过渡金属的催化剂的组合使得该系统与极性官能团更相容。这通过引入有机染料作为端基以产生有色聚乙烯材料来突出。
Highly tunable end-functionalized polyethylene molecules are directly synthesized via chain-transfer polymerization of ethylene with silanes as chain-transfer agents catalyzed by a pentamethyl cyclopentadienyl cobalt phosphite alkyl catalyst. A series of polymerizations and kinetic studies of the different elementary steps involved in the catalytic cycle were performed to establish the methodology and to gain a deeper understanding of the reaction mechanism. The rate of the chain transfer, and thus the polymer length, can be tuned independently by varying the silane concentration or substituents. The combination of a chain-transfer methodology with a late transition-metal-based catalyst makes this system more compatible to polar functionality. This is highlighted by the introduction of an organic dye as end group to yield a colored polyethylene material.