单一位点第Ⅳ族聚烯烃催化剂研究进展

Advances on single-site group Ⅳ catalysts for olefin polymerization

聚烯烃主要通过第Ⅳ族金属催化剂进行配位聚合制备,单一位点催化剂一直为研发热点。该类催化剂通常被分为茂金属催化剂和后茂金属催化剂,并逐渐由单金属催化剂发展成双金属催化剂。介绍了茂金属催化剂和后茂金属催化剂的分类、结构特征以及配体结构对烯烃聚合性能和聚烯烃结构的影响。其中,茂金属催化剂的结构对称性对烯烃聚合影响较大,而后茂金属催化剂的配体取代基对烯烃聚合影响较大。建议加强后茂金属催化剂的设计合成,并尽快应用到聚烯烃新材料产业化中。

Polyolefins are mainly produced by group lV metal catalysts. A single site catalyst has been a hot area for years. As for single site group Ⅳ metal catalysts, they are generally considered to have two types： metallocene catalysts and post-metallocene catalysts, evolving from scaffolds with single active center to those with double active centers. This review covered the main characteristics of the two types of catalysts such as classification, structures, influences of ligands substitutes to polymerization processes and the polymer properties. For metallocene catalysts, their symmetry is a key factor in the olefin polymerization, while the substituted groups of post-metallocene ligands impact a lot on the properties of polymer. We should take more attention on the synthesis of post metallocene catalysts and their application in new materials such as polyolefin elastomers.