| Summary: | Postsynthesis modification of solid polymethylaluminoxane (sMAO) with tris(pentafluorophenyl)borane or pentafluorophenol produces highly active metallocene supports "sMMAOs" for use in slurry-phase ethylene polymerization. Characterization of the sMMAOs using elemental analysis, BET isotherm, SEM-EDX, diffuse FT-IR, and solid-state NMR spectroscopy reveals that the surface methyl groups are exchanged for C 6 F 5 and C 6 F 5 O moieties respectively, giving a material with reduced aluminum content and a lower specific surface area than sMAO. rac-Ethylenebis(1-indenyl) zirconium dichloride, {(EBI)ZrCl 2 } immobilized on B(C 6 F 5 ) 3 - and C 6 F 5 OH-modified sMAO displayed activity increases of 66% and 71% respectively for ethylene polymerization compared to the same zirconocene catalyst precursor on unmodified sMAO. In the case of B(C 6 F 5 ) 3 -modified sMAO, this enhanced polymerization activity is accompanied by excellent control of polymer particle size and morphology, and a small decrease in polymer molecular weight and polydispersities.
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