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Heterogeneous Polymerization of Ethylene and 1‐Hexene with Me 3 SiCp 2 ZrH 3 AlH 2 /SiO 2 Activated with MAO
Author(s) -
González Rebeca,
Morales Elsa,
García Maricela,
Revilla Javier,
Charles Rogelio,
Collins Scott,
Cadenas Gregorio,
Lugo Luis,
Pérez Odilia
Publication year - 2009
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200950913
Subject(s) - copolymer , polymerization , ethylene , catalysis , polymer , polymer chemistry , thermal stability , materials science , chain transfer , metallocene , hydrogen , chemistry , chemical engineering , organic chemistry , radical polymerization , engineering
The aluminohydride of zirconocene Me 3 SiCp 2 ZrH 3 AlH 2 was supported on pre‐treated SiO 2 , and its catalytic activity for ethylene polymerization and ethylene‐1‐hexene copolymerization was evaluated in order to compare with the corresponding activity of the complex in solution. As expected for systems based on metallocenes, the aluminohydride of zirconocene complex showed higher activity in solution than in suspension, however its thermal and kinetic stability was significantly increased. The effect of the co‐catalyst concentration (MAO) on the activity and the molecular weight of the polymers are also reported in this study, finding that in heterogeneous phase low concentrations of MAO were used to activate the pre‐catalyst. The MW of the polymers and copolymers synthesized with the supported Me 3 SiCp 2 ZrH 3 AlH 2 /SiO 2 could be controlled by adding molecular hydrogen (H 2 ) as chain transfer agent in the polymerization and copolymerization reactions.