Supported bis(peralkylindenyl)metallocene catalysts for slurry phase ethylene polymerisation

Abstract

A series of bis(peralkylindenyl)zirconocene and hafnocene complexes were synthesised and characterised by NMR spectroscopy, mass spectrometry and elemental analyses. 3-ethyl-2,4,5,6,7-pentamethylindanone, (3-EtInd#)O; 3-ethyl-2,4,5,6,7-pentamethylindene, (3-EtInd#)H, and rac-3-ethyl-2,4,5,6,7-pentamethylindenylhafnium dichloride, rac-(3-EtInd#)2HfCl2, were also characterised by X-ray crystallography. rac- and meso-(3-EtInd#)2MCl2 (M=Zr or Hf) were obtained from the reaction of (3-EtInd#)Li with ZrCl4 or HfCl4. The group 4 metallocenes were then reacted with methylaluminoxane-functionalised silica (SSMAO) to afford silica supported catalysts. A mixture of rac- and meso-(3-EtInd#)2ZrCl2 supported on SSMAO demonstrated an initial polymerisation activity of 250kgPE/molM/h/bar. At 70°C, using rac-(3-EtInd#)2ZrCl2, solution phase polymerisation activities were twenty times faster than slurry phase polymerisation using SSMAO-rac-(3-EtInd#)2ZrCl2 (1243 and 75kgPE/molZr/h/bar respectively).