Copolymerization behavior of Cp₂ZrCl₂/MAO and [(CO)₅WC(Me)OZrCp₂Cl]/MAO: a comparative study on ethylene/1-pentene copolymers

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• 作者：Nyambeni Luruli ; Lars-Christian Heinz ; Valé ; rie Grumel ; Robert Brü ; ll ; Harald Pasch and Helgard G. Raubenheimer
• 关键词：Ethylene/1-pentene copolymers ; Short chain branching distribution (SCBD) ; Automated preparative molecular weight fractionation (PMWF)
• 刊名：Polymer
• 出版年：2006
• 出版时间：3 January 2006
• 年：2006
• 卷：47
• 期：1
• 页码：56-66
• 全文大小：318 K

文摘

Ethylene/1-pentene copolymers were synthesized using Cp₂ZrCl₂(1)/MAO and [(CO)₅WC(Me)OZr(Cp)₂Cl](2)/MAO catalyst systems. The copolymers were characterized by SEC, DSC, FTIR and ¹³C NMR spectroscopy. The copolymers synthesized with [(CO)₅WC(Me)OZr(Cp)₂Cl](2)/MAO had higher average molecular weights and broader polydispersities compared to those produced with Cp₂ZrCl₂(1)/MAO. The chemical heterogeneity was investigated by SEC-FTIR and fractionation techniques. All copolymers showed a higher incorporation of the 1-pentene in the low molecular weight fraction as revealed by SEC-FTIR. Crystallization analysis fractionation (CRYSTAF) showed a broad chemical composition distribution (CCD) for all the copolymers synthesized with these two catalyst systems. Selected copolymers were also analyzed using an automated preparative molecular weight fractionation.