Calleja, G.Aguado, JoséCarrero, A.Moreno, J.2010-05-032010-05-032005Studies in Surface Science and Catalysis 158 (2005) 1453-1460http://hdl.handle.net/10115/3867Ethylene polymerization catalysts have been prepared by incorporation of chromium (III) acetylacetonate onto siliceous SBA-15 swelled mesoporous materials. Catalysts characterization includes DRX, FTIR, UV-vis spectroscopy, nitrogen physisorption, TGA and ICP analysis. Chromium anchorage through H-bonds was observed in Cr/SBA-15 catalyst prepared by incipient wetness impregnation. On the contrary, when catalysts were prepared by grafting, a ligand exchange reaction may occur. For similar chromium contents, catalyst prepared by grafting showed higher polymerization activity than catalyst prepared by incipient wetness impregnation. Regarding polymer properties, Cr/SBA-15 catalyst prepared by impregnation gave polyethylene with slightly higher molecular weight, polydispersity, bulk density and melting temperature than polyethylene obtained from grafted catalystenAtribución-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