Copolymerization of ethylene or propylene and norbornene (NB) was carried out with stereospecific zirconocene catalysts rac-ethylenebis(indenyl)zirconium dichloride, rac-dimethylsilylenebis(indenyl)zirconium dichloride (2), rac-dimethyl-silylenebis(2-methylindenyl)zirconium dichloride, and diphenylmethylene(cyclopentadienyl)(9-fluorenyl)zirconium dichloride combined with cocatalysts at 40°C. Temperature-rising elution fractional of the copolymers was carried out with cross-fractionation chromatography with o-dichlorobenzene as a solvent, and a broad distribution of the copolymer composition was detected. The fraction eluted at lower temperature contained higher NB. The effect of the polymerization time was examined in the ethylene-NB copolymerization with catalyst 2, and the higher-temperature elution fraction increased with increasing polymerization time.
|ジャーナル||Journal of Polymer Science, Part A: Polymer Chemistry|
|出版ステータス||Published - 2003 2月 1|
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