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在C5系列的综合利用中近年来备受关注的环烯烃共聚物是最具有发展潜力的高端产品之一。本文评述了用于乙烯和降冰片烯类共聚合体系新型加成催化剂的最新进展,包括茂金属催化剂、非茂金属催化剂和后过渡金属催化剂三大类。开发新型半夹心型催化剂是茂金属研究领域的热点,目前主要有两类:限定几何构型催化剂(CGC)以及Cp′MX3和Cp′M(R)X2(Cp′=茂基或取代茂基;M=Ti,Zr,Hf;X=卤素或烷基;R=OAr,NR2,NPR3)。非茂金属催化剂则具有亲电能力更强的活性中心及更开放的配位空间,通常具有更高的NB插入率,甚至在一定条件下具有类活性聚合的特征。后过渡金属催化剂由于对氧(或Lewis酸)更不敏感,导致对极性基团有更好的耐受性。此外,重点围绕配体结构对催化特性的影响,对如何提高分子量和环烯烃的有效插入率及其序列结构的调控等进行了对比和剖析,并展望其今后发展趋势。
In the C5 series of comprehensive utilization in recent years, much attention cycloolefin copolymer is one of the most promising high-end products. In this paper, the recent advances in new addition catalysts for copolymerization of ethylene and norbornenes are reviewed, including metallocene catalysts, non-metallocene catalysts and post-transition metal catalysts. The development of new type of semi-sandwich catalysts is a hot topic in the field of metallocene research. There are currently two main types of catalysts: CGC and Cp’MX3 and Cp’M (R) X2 (Cp ’= cyclopentadienyl or substituted cyclopentadienyl; M = Ti, Zr, Hf; X = halogen or alkyl; R = OAr, NR2, NPR3). Non-metallocene catalysts, on the other hand, have more electrophilic active centers and more open coordination spaces, usually with higher NB insertion rates, and even have a living-polymerization-like character under certain conditions. Late transition metal catalysts lead to better resistance to polar groups due to their less susceptibility to oxygen (or Lewis acids). In addition, we focus on the influence of the ligand structure on the catalytic properties, and compare and analyze how to increase the molecular weight and the effective insertion rate of cycloalkene and its sequence structure, and look forward to its future development trend.