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Pressure effects on termination mechanisms during ethene polymerization catalyzed by dicyclopentadienylzirconium dichloride/methylaluminoxane
Author(s) -
Thorshaug Knut,
Rytter Erling,
Ystenes Martin
Publication year - 1997
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.1997.030180813
Subject(s) - methylaluminoxane , polymerization , polymer chemistry , catalysis , chemistry , materials science , metallocene , organic chemistry , polymer
Abstract Polymerization of ethene catalyzed by dicyclopentadienylzirconium dichloride/methylaluminoxane was performed in toluene at 50°C under 0.38–8.95 bar ethene. Both Fourier‐transform infrared spectroscopy and gel‐permeation chromatography showed that the molecular weight is independent of the ethene pressure (concentration). The trans ‐vinylene unsaturation content increased as the pressure decreased. Termination by β‐H transfer to a coordinated monomer and a kinetically controlled isomerization reaction are suggested, in order to explain the observations.