降冰片烯与丙烯共聚合的研究进展

Research progress of norbornene and propylene copolymerization

继高活性茂金属催化体系成功开发以降冰片烯和乙烯共聚物为代表的高性能环烯烃共聚物以来,降冰片烯与其他α-烯烃如丙烯的共聚物研究也备受学术界和工业界的重视。本文介绍了降冰片烯与丙烯共聚合的催化剂和聚合机理等方面的最新研究进展,包括各种不同结构的茂金属催化剂催化降冰片烯与丙烯共聚合的特点及其共聚物的结构分析。C2-对称和Cs-对称的茂金属催化剂催化降冰片烯与丙烯共聚合时链转移反应较多,以致催化活性较低,所得的聚合产物分子量偏低。采用限定几何构型茂金属柄型-二甲基亚甲硅基(芴基)(氨基)二甲基钛催化剂进行降冰片烯与丙烯共聚合时,催化活性可高达107 g polymer·(mol cat·h)-1,所得共聚物的相对分子质量超过20万,降冰片烯含量可达70%(mol)且玻璃化转变温度高。

Since the highly active metallocene catalysts have successful opened up the possibility to synthesize norbornene-ethylene copolymer as a typical representative of the cyclic-olefins copolymer, copolymerization of norbornene with otherα-olefin such as propylene is also paid more attention by the academics and industries. In this paper, the research progress of norbornene and propylene copolymerization in recent years is briefly introduced, including the copolymerization characteristics catalyzed by a variety of different structures metallocene catalysts and the structure analysis of the resultant copolymers. For the C2-symmetric and Cs-symmetric metallocene catalyst, the chain transfer reaction of norbornene and propylene copolymerization leads to low catalytic activity and low molecular weight of the obtained products. With the contrained geometry metallocene ansa-dimethylsilylene（fluorenyl）（amido）dimethyltitanium-based derivatives catalyzing copolymerization of norbornene and propylene, catalytic activity can be up to 107 g polymer·（mol cat·h）-1, and the resulting copolymer with a molecular weight of more than 200000, a norbornene content of up to 70%（mol） and high glass transition temperature can be obtained.