Van Grieken, R.Carrero, A.Suarez, I.Paredes, B.2010-05-072010-05-072007European Polymer Journal 43 (2007), 1267-1277http://hdl.handle.net/10115/3887The catalytic system methylaluminoxane (MAO) and bis(n-butylcyclopentadienyl)zirconium dichloride ((nBuCp)2ZrCl2) was immobilized on commercial silica, silica-alumina and aluminophosphate calcined at different temperatures. The properties of the supports were determined by using N2 adsorption-desorption isotherms at 77 K, FT-IR spectroscopy and SEM. After aluminium and zirconium impregnation, the catalysts were analyzed by ICP-AES, FT-IR and UV-Vis spectroscopy. Ethylene polymerizations were carried out in a Schlenk tube at 70 ºC and 1.2 bar of ethylene pressure. The polyethylene obtained was characterized by GPC, DSC and SEM. Catalysts supported on silica-alumina exhibited higher polymerization activity than those supported on silica and aluminophosphate. Besides, the activity of MAO/(nBuCp)2ZrCl2 catalytic system supported on silica-alumina and aluminophosphate decreased strongly with support calcination temperature, while remained almost constant when silica was employed as support. All these experimental features suggest a role of the support acid properties and hydroxyl group population in the generation of active polymerization species.enAtribución-NoComercial-SinDerivadas 3.0 Españahttp://creativecommons.org/licenses/by-nc-nd/3.0/es/Materialesinfo:eu-repo/semantics/article10.1016/j.eurpolymj.2007.01.008info:eu-repo/semantics/openAccess23 Química