复配催化体系制备双峰分布的聚乙烯

Mixed Catalytic Systems for Preparing Polyethylene with Bimodal Molecular Weight Distribution

利用茂金属加合物和一种Ziegler-Natta钛系催化剂复配而成的催化体系 ,制备相对分子质量呈双峰分布的聚乙烯。考查了复配催化体系中茂金属加合物和钛系催化剂的配比对聚合物相对分子质量、相对分子质量分布及结构性能的影响。

Ethylene polymerization and ethylene/1-hexene co-polymerization using a mixture of metallocene adduct(APE-1) and Zeigler-Natta Ti catalyst were studied.In the case of copolymerization,the catalyst activity increases with decreasing n(Zr)/n(Ti)which shows significant influence on the molecular weight and molecular weight distribution of the copolymer.Catalyst systems with different n(Zr)/n(Ti) give different types of kinetics curve,and have an obvious effect on the flow properties of copolymers.In the case of ethylene homopolymerization,the product exhibits bimodal molecular weight distribution.