内给电子体在气相聚乙烯催化剂中作用的研究

采用浸渍法制备工艺,在MgCl2/SiO2复合载体齐格勒-纳塔(Z-N)催化剂制备过程中加入了醇、酯、醚和硅烷四类内给电子体,考察了不同内给电子体对气相聚乙烯催化剂的活性、产物堆密度、细粉含量的影响;结果表明:正硅酸乙酯作为聚乙烯催化剂的内给电子体效果较好,催化剂活性达到3447.5g·PE/g·Cat·h,聚合物堆密度达到0.33g·cm-3,细粉含量仅占0.052%,电子显微镜下催化剂颗粒呈均匀的球形。

Study on the role of internal electron donor to gas phase polyethylene catalyst

Four types of internal electron donors, alcohols, esters, ethers and silanes were added into the preparation of MgCl2/SiO2 complex support Ziegler-Natta catalyst for ethylene gas phase polymerization through the same preparation techniques. The influence of different types of internal electron donor on the catalyst activity, polymer bulk density and powder content were also investigated. The performance of tetraethoxy-silicone as the internal electron donor of polyethylene catalyst is better than that of the others. The activity of the catalyst was 3447.5 g. PE/g. Cat.h, Polymer bulk density was up to 0.33g.cm-3 and powder content was only 0.052%.The granule of the catalyst is sphericity uniformly.