Strong influences of polymerization temperature on ethylene/1-hexene copolymerization catalyzed by (2-PhInd)_2ZrCl_2/methyl aluminoxane  

作　　者：叶坚定 范志强 王伟 

机构地区：[1]Institute of Polymer Science, Zhejiang University, Hangzhou 310027, China

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2005年第10期1009-1014,共6页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：Project (Nos. 29734144 and 20274037) supported by the National Natural Science Foundation of China

摘　　要：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 co- polymer 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 mo- lecular weight distribution. A mechanism model based on ligand rotation hindered by the propagation chain has been proposed to qualitatively explain the observed phenomena.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.

关 键 词：Catalysis Catalysts ETHYLENE Molecular weight distribution MONOMERS Thermal effects 

分 类 号：O631[理学—高分子化学]