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Effects of Cocatalysts on Propene Polymerization with [ t ‐BuNSiMe 2 (C 5 Me 4 )]TiMe 2
Author(s) -
Ioku Atau,
Hasan Tariqul,
Shiono Takeshi,
Ikeda Tomiki
Publication year - 2002
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20020301)203:4<748::aid-macp748>3.0.co;2-g
Subject(s) - polymerization , methylaluminoxane , polymer chemistry , propene , molar mass distribution , chain transfer , chemistry , polymer , monomer , degree of polymerization , bulk polymerization , materials science , radical polymerization , organic chemistry , catalysis , metallocene
Propene polymerization was conducted using [ t ‐BuNSiMe 2 (C 5 Me 4 )]TiMe 2 combined with various cocatalysts at 0°C, and kinetic profiles were investigated under atmospheric pressure of propene in a semibatch system. Dried methylaluminoxane (MAO), which was free of Me 3 Al, was found to be more active than the standard MAO system, resulting in a steady polymerization rate and giving higher molecular‐weight polypropenes. Sampling experiments during the polymerization showed an almost linear relationship between the number‐average molecular weight, M̄ n , and polymerization time while retaining a narrow molecular‐weight distribution, whereas the results of batch polymerization with different monomer concentrations and post‐polymerization indicated that chain transfer reactions occurred to a minor degree under these polymerization conditions. Additive effects of trialkylaluminium on the dried MAO system showed that the polymer yield was increased by the addition of i ‐Bu 3 Al and Oct 3 Al and decreased by Me 3 Al and Et 3 Al. All of the trialkylaluminium compounds increased the number of polymer chains ( N ), and the Et 3 Al system showed the highest N value with the lowest M̄ n value.