Synthesis of Silica‐Supported Metallocene Catalysts for Olefin Polymerization

Four supported metallocene catalysts were synthesized directly on silica [Si(CpZrCp), Si(CpZrInd), Si(IndZrCp), and Si(IndZrInd)]. The first ligand was chemically tethered to silica (internal ligand) while the second was free from silica (external ligand). The polymerization of ethylene and the copolymerization of ethylene with hexene were investigated. The activity of the catalysts and the molecular weights of the polymers were found to depend on the position of the ligands. In all cases, high‐molecular‐weight polyethylene with moderate polydispersity was obtained. Moreover, the copolymerization of ethylene with hexene provided a homogeneous polymer. Reaction of ZrCl4(OC4H8)2 with modified silica (SiCp). magnified image Reaction of ZrCl4(OC4H8)2 with modified silica (SiCp).