Study On The Propylene Polymerization And Polymer Of High Performance Z-N Catalyst

In the present work, N and DQ catalyst cooperated with methyl cyclohexyl 2-methoxy silane (CHMMS), 2-cyclopentyl 2- methoxy silane (DCPMS) respectively for propylene homo-polymerization and propylene/ethylene co-polymerization have been studied. The effect of nucleating agents on the mechanical property of polymer has been investigated too. A method for the evaluation of the distribution of ethylene in the co-polymer of propylene and ethylene has been brought out.It was found that, under same slurry polymerization condition with n-heptane as the solvent, the molecular weight and structure of ethylene-propylene copolymer produced by different catalyst system were different, the polymer produced by N+DCPMS catalyst system showed the biggest molecular weight and the simplest molecular structure. Furthermore, some more almost pure polyethylene was produced. That produced with DQ+CHMMS system showed the smallest molecular weight and the most complex molecular structure.The bulk of homo-polypropylene and propylene-ethylene co-polymer were produced with different catalyst systems on a continuous polypropylene pilot plant. It was found that the impact property of homo-polypropylene was affected by it's molecular weight (Mw). Those with bigger Mw showed better anti-impact property. The hydrogen response of different catalyst systems is different. N+DCPMS system behaves the worst hydrogen response. ND catalyst without external donor, N+CHMMS and DQ+CHMMS systems have the almost same hydrogen response. The stiffness of polypropylene produced with different catalyst systems is different. That produced with N+DCPMS has the best stiffness. As far as multi phase polymerization is concerned, the molecular weight and structure of the co-polymer are affected by the hydrogen concentration and the catalyst system. As a result, the mechanical properties of the polymer are affected. The glass temperature of the rubber phase in the copolymer can be decreased by lower hydrogen concentration in the gas phase reactor. The distribution of ethylene in the backbone of the copolymer produced...