Journal of Catalysis, Vol.362, 129-145, 2018
2D-aluminum-modified solids as simultaneous support and cocatalyst for in situ polymerizations of olefins
The reaction of methylaluminoxane (MAO) with 2D and 3D inorganic supports such as magadiite, [Al]magadiite, n-alkyl-AIPO-kanemite, MCM-41 and MCM-48 was investigated by solid state NMR spectroscopy. The products obtained from the reaction of aluminum-modified magadiite and MAO were dominated by surface species of the type Si OCH3/Al-OCH3. A mechanism for the surface reactions of MAO is proposed. The MAO-modified solids were employed for the polymerization of ethylene with constrained geometry catalyst (CH3)(2)Si(C29H36)(N-Bu-t)ZrCl2 (1). This constrained geometry catalyst produced remarkably high activity comparable to the homogeneous system. MAO-modified [Al]-magadiite seems to have an increased acidity. [Al]-magadiite as well as n-alkyl-AIPO-kan, when employed as supports for Ph2C (C5H4)(C29H36)ZrCl2 (2), kept a constant activity at low cocatalyst/Zr ratios whereas pure-silica supports led to a rapid decay in activity. Transmission electron microscopy (TEM) confirmed the formation of PE nanocomposites on magadiite-supported catalyst 2. (C) 2018 Elsevier Inc. All rights reserved.