Study Of New Full Density Polyethylene Catalyst

Metallocene catalyst PS-DVB-MC on polymer support was prepared , then the catalyst was thoroughly characterized and analyzed in the convelltional methods , such as MS , FT- IR , NMR , SEM , XPS and 50 forth. Ethylene homo-olymerization and ethylene / l-hexene co-polymerization in sluny phase was investigated in the stainless steel reactor at high pressure of ethylene. the allyl substituted cyclopentadienyl ligand was synthesized in the method of phase transfer , then the metallocene compound MC was accordingly synthesized on the basis of the ligand . The heterogeneous catalyst PS-DVB-MC was prepared via co-polymerization of metallocene compound MC , styrene and divinyl-benzene in the presence of azodilsobutyronitrile ( AIBN ) , which was the initiator of free radical . Moreover , all variety of semi-roducts and products in the process of preparation were characterized and analyzed in detail. The kinetic behaviors of ethylene homo- olymerization and ethylene / l-hexene co-polymerization , catalyzed by the metallocene catalyst PS-DVB-MC in an 0.5 L stainless steel reactor , were studied. The effects of polymerization conditions on ethylene polymerization , such as concentration of catalyst , temperature of polymerization , pressure of ethylene , molar ratio of AI / Z r , etc . , were also investigated . Some leading results were as follows : the activity of the catalyst PS–DVB- MC for ethylene homo-polymerization was high ( 1.053 x 107 gPE / mol Zr·h ) , but the molar ratio of AI / Zr was low ( 350:1 ) ; the catalytic ability for ethyleneα-olefin ( such as l hexene etc . ) co-olymerization was great , and the corresponding activity come up to a maximum of 1.753 x 107 gPE / mol Zr·h while concenlration of l-hexene was 0.080 mol / L ; the molecular weight of polyethylene was about 180,000 , meanwhile the molecular weight distribution was narrow ( 2.19 ) ; the bulk density of polyethylene and ethylene / l-hexene co -polymer were 0.25 and 0.34 respectively . The teclmological parameters for ethylene polymerization in sluriy phase were optimized , 50 that the significant data of basic researches were available for the subsequent pilot plant and scale-up experiments in the near future . on balance , the metallocene catalyst PS-DVB-MC on polymer support 15 a kind of single-site type catalysts for olefin polymerization , and has a great industrial potential .