FI催化剂配体的研究进展

FI催化剂作为一类新型聚烯烃催化剂,具有高活性、耐高温等特性,在催化聚合方面表现出良好的性能,不但可以催化乙烯与极性及非极性单体共聚,而且可以通过改变主催化剂苯氧基亚胺配体的结构,得到具有不同结构的聚合物。本文介绍了FI主催化剂的基本结构、合成方法、结构与催化性能的关系以及基于苯氧基亚胺配体基本结构的新型催化剂的研究进展。     

聚烯烃弹性体催化剂研究进展

聚烯烃弹性体(POE)是一类有高性能、高附加值的高分子材料,随着其应用领域的不断拓展,在国内外得到迅速发展,国内各大相关企业纷纷投入巨资进行研究开发。作为聚烯烃产业核心技术的催化剂,核心技术目前主要控制在西方公司手中,开发具有自主知识产权的催化剂是当前的POE领域研究热点。为了给国内同行提供参考,课题组结合国内外的研究工作,对目前主流的POE催化剂——限定几何构型茂金属催化剂(CGC) 、桥连双配体结构茂金属和苯氧基亚胺催化剂(FI)的发展历程进行了评述,对近五年这三类催化剂的微观结构、催化活性以及结构与催化性能的关系,特别是催化乙烯/1-辛烯共聚反应的活性以及1-辛烯插入率进行详细的比较,考察了各类不同的有机配体对催化剂催化行为、聚合物组成的影响,揭示了均相催化条件下通过改变配体结构以提高聚合反应温度和1-辛烯插入率的技术方案,本文摘录了67篇文献,涉及到109种催化剂,相信本文的工作对于国内同行设计、合成新型POE催化剂将具有重要的参考作用。     

Linear/branched Block Polyethylene Produced by α-Diimine Nickel(Ⅱ)Catalyst and Bis(phenoxy-imine) Zirconium Binary Catalyst System in the Presence of Diethyl Zinc

In order to promote development of linear/branched block polyethylenes based on new catalytic systems,we synthesized a novel α-diimine nickel(Ⅱ) complex with isopropyl substituents on ortho-N-aryl and hydroxymethyl phenyl substituents on para-N-aryl structures.The activity of α-diimine nickel(Ⅱ) catalyst was 3.02×106 g·molNi-1·h-1 at 70 ℃,and resultant polyethylene possessed 135/1000C branches.The linear/branched block polyethylenes were synthesized from ethylene polymerization catalyzed by the α-diimine nickel(Ⅱ) complex/bis(phenoxy-imine) zirconium in the presence of diethyl zinc.With the addition of ZnEt2 (from 0 to 400),the melting peak of resultant polyethylene changed from a single melting peak to bimodal melting peaks.The molecular weights of resultant polyethylene ranging from 26.8 kg/mol to 17.1 kg/mol and PDI values varying gradually from 24.4 to 15.2 were obtained via adjusting ZnEt2 equiv.and molar ratio of two catalysts.In addition,the branching degree of the polyethylene increased from 13/1000C to 56/1000C with the increase of the proportion of α-diimine nickel(Ⅱ) catalyst.Using this binary catalyst system,the reaction temperature of chain shuttling polymerization can be carried out at 70 ℃,which is more conducive to industrial application.