High catalytic activity of SBA-15-supported metallocene toward ethylene polymerization: The effect of the ordered porous structure of the support

The catalytic activity of the (nBUCP)(2)ZrCl2 metallocene Supported on ordered SBA-15 mesoporous silica and on traditional amorphous silica toward the polymerization of ethylene is Studied. High activity values were obtained with the SBA-15-supported catalyst (6953-8407 kg mol(-1) Zr bar(-1) h(-1)), which were significantly higher than those presented by the catalyst supported on amorphous silica (959-4234 kg mol(-1) Zr bar(-1) h(-1)). The highly ordered mesoporous structure of SBA-15 affords a more homogeneous distribution of the metallocene on the Support Surface and improves accessibility during metallocene activation and monomer insertion. Polyethylene (PE) synthesized with the SBA-15-supported catalyst retains the molecular weight distribution of the PE produced with the single-site homogeneous metallocene, making the SBA-15-supported catalyst a promising heterogeneous metallocene system. (C) 2008 Elsevier B.V. All rights reserved,