A Novel Linear−Hyperbranched Multiblock Polyethylene Produced from Ethylene Monomer Alone via Chain Walking and Chain Shuttling Polymerization

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• 作者：Anguo Xiao^† ; ^‡ ; ; Li Wang*^† ; ; Qingquan Liu^† ; ; Haojie Yu^† ; ; Jianjun Wang^† ; ; Jia Huo^† ; ; Qiao
• 刊名：Macromolecules
• 出版年：2009
• 出版时间：March 24, 2009
• 年：2009
• 卷：42
• 期：6
• 页码：1834-1837
• 全文大小：122K
• 年卷期：v.42,no.6(March 24, 2009)
• ISSN：1520-5835

文摘

A novel linear−hyperbranched multiblock polyethylene was prepared from ethylene monomer alone via chain walking and chain shuttling polymerization in the presence of chain transfer agent (ZnEt₂). In the binary catalyst system, α-diimine nickel(II) bromide complex (CatA) produced chain segments with hyperbranched architecture via chain walking, and ansa-ethylenebis(1-η⁵-indenyl)zirconium dichloride (CatB) yielded linear chain segments, while ZnEt₂ facilitated chain exchanges between two active metal centers. The resultant multiblock polyethylene featured a narrow weight distribution and useful combining properties of linear and branched polyethylene. Further, polymers were expediently prepared in an effective and economical polymerization process from ethylene monomer alone.