Preparation Of Ethylene Slurry Polymerization Ziegler-Natta Catalysts And Their Polymerization Performance Study

This thesis is based on the study of MgCl₂support titanium Ziegler-Natta catalysts，and tetraethylorthosilicate（TEOS） which is a kind of electron donor compound was added into traditional titaniumZiegler-Natta catalysts. A new and efficient magnesium chloride catalyst supported on titanium wasprepared, this catalyst keeps the advantages of Ziegler-Natta catalysts, such as high activity and high BD,meanwhile improves structure and property of catalysts. Producing of high property polyethylene productswith GZ catalysts, in order to meet the needs of the polymerization process of innovation and thehigh-level of performance of market polyethylene products.In this thesis, the new and efficient preparation process of titanium catalyst supported on MgCl2wasstudied systematically, investigating the factors of polymerization temperature, Al/Ti mole ratio，hydrogenand1-butene amount on the influence of catalyst performance. The morphology and pore structure of thecatalyst were characterized by SEM, BET, and DSC, used to study the structure and properties of thepolymer. The result showed that the new type of catalyst that added into electron donor obtained highcatalytic activity and high specific surface area. optimized polymerization temperature is80℃and Al/Timolar ratio is120. Catalyst is sensitive to concentration of H2, we can control Mw of polymer by changingthe concentration of H2. The copolymerization of ethylene and1-butene, when GZ catalyst is existing,show high activity, Products have random branched structure. These advantages can be used on producingBimodal/Broad MWD Polyethylene. The MWD of polymer has two peaks. Fine powder content is3.2%when the concentration of1-butene is1.3%.