Study of propylene polymerization using zirconocenes Ph2CCpFluZrCl2 and rac-Me2Si(2-Me,4-PhInd)2 ZrCl2
activated by combined MAO/TIBA cocatalyst (in English)
Polimery 2008, No 5, 358
Zirconocenes Ph2CCpFluZrCl2 (1) and rac-Me2Si(2-Me,4-PhInd)2ZrCl2 (2) first preactivated with methylalumoxane (MAO) at rather low AlMAO/Zr molar ratio=20-300mol/mol and further activated either traditionally with MAO or non-traditionally with triisobutylaluminum (TIBA) have been studied and compared from the point of view of catalysts' activity in propylene polymerizations. The dependence of catalyst productivity on molar ratio of components has been analyzed. It has been shown by 1H NMR that mainly tetraisobutyl alumoxane (TIBAO) was formed at about equimolar MAO/TIBA ratios thus assuming TIBAO participation in initiation of the catalysts in examined systems. It has been shown that TIBAO provides higher catalytic activity compared to MAO at lower cocatalyst (activator)/catalyst molar ratios and allows conducting of propylene polymerization in the medium of heptane.
Key words: propylene polymerization, metallocene catalyst, methylalumoxane, triisobutylaluminum, catalyst activity
Study of propylene polymerization using zirconocenes Ph2CCpFluZrCl2 and rac-Me2Si(2-Me,4-PhInd)2 ZrCl2 activated by combined MAO/TIBA cocatalyst (in English)