SILICA-SUPPORTED NICKEL AND ZIRCONIUM CATALYSTS FOR BRANCHED POLYETHYLENE

• 作 者: 孙文华 State Key Laboratory of Engineering Plastics The Center for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China
• 出 处: Chinese Journal of Polymer Science
• 发表日期: 2003年04期
• 关键词: nickel polymerization polyethylene chains selectivity catalysis silica Ziegler o

8-Aminoquinoline nickel dichloride and bis(cyclopentadienyl)zirconium dichloride (Cp_2ZrCl_2) were supportedsimultaneously on silica to produce branched polyethylene successfully by combined polymerization. The supportedpolymerization results showed that the molecular weight of polyethylene increased while the molecular weight distributionbecame wider and the molecular chains of oligomers remaning in the final solution became shorter as compared to theoligomers obtained in polymerization processes with pure 8-aminoquinoline nickel dichloride catalysis, as well as theCp_2ZrCl_2 and nickel combination system. With decreasing amount of Ni catalyst in the supported catalyst, the molecular chains of oligomers in the resulting solution became shorter, while α-olefin selectivity increased.

8-Aminoquinoline nickel dichloride and bis (cyclopentadienyl) zirconium dichloride (Cp_2ZrCl_2) were supportedsimultaneously on silica to produce branched polyethylene successfully by combining polymerization. The supported polymerization result showed that the molecular weight of polyethylene increased while the molecular weight distributionbecame wider and the molecular chains of oligomers remaning in the final solution became shorter as compared to theoligomers obtained in polymerization processes with pure 8-aminoquinoline nickel dichloride catalysis, as well as theCp_2ZrCl_2 and nickel combination system. With decreasing catalyst of the catalyst, the molecular chains of oligomers in the resulting solution became shorter, while α-olefin selectivity increased.