关键词: 降冰片烯-丙烯共聚合, 茂金属催化剂, 序列结构

Abstract:

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 other α-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 C_s-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.

Key words: norbornene-propylene copolymerization, metallocene catalyst, sequence structure