Journal of Zhejiang University SCIENCE
(ISSN 1009-3095, Monthly)

2005   Vol. 6B   No. 10   p.1009-1014

Strong influences of polymerization temperature on ethylene/1-hexene copolymerization catalyzed by (2-PhInd)₂ZrCl₂/methyl aluminoxane

YE Jian-ding^†, FAN Zhi-qiang^†‡, WANG Wei

(Institute of Polymer Science, Zhejiang University, Hangzhou 310027, China)
^†E-mail: stonestone5678@yahoo.com.cn; fanzq@zju.edu.cn
Received July 27, 2005; revision accepted Aug. 18, 2005

Abstract: Ethylene/1-hexene was copolymerized by an unbridged zirconocene, (2-PhInd)₂ZrCl₂/MAO (methyl aluminoxane) at 0 °C and 50 °C respectively. High copolymerization activity and 1-hexene incorporation were observed at 0 °C, with the copolymer formed having random sequence distribution and narrow molecular weight distribution. Ethylene polymerization at 50 °C showed high activity, but copolymerization at 50 °C showed much lower activity, which decreased sharply with increasing 1-hexene concentration in the monomer feed. Copolymer formed at 50 °C showed blocky sequence distribution and broad molecular weight distribution. A mechanism model based on ligand rotation hindered by the propagation chain has been proposed to qualitatively explain the observed phenomena.

Key words: Unbridged metallocene, Ethylene, 1-Hexene, Copolymerization, Temperature effect
doi:10.1631/jzus.2005.B1009             CLC number: O63

^‡ Corresponding Author