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

摘要

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-Et)Ind(#)-}=O; 3-ethyl-2,4,5,6,7-pentamethylindene, ((3-Et)Ind(#))H, and rac-3-ethyl-2,4,5,6, 7-pentamethylindenylhafnium dichloride, rac-((3-Et)Ind(#))(2)HfCl2, were also characterised by X-ray crystallography. rac- and meso-((3-Et)Ind(#))(2)MCl2(M = Zr or Hf) were obtained from the reaction of ((3-Et)Ind(#))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-Et)Ind(#))(2)ZrCl2 supported on SSMAO demonstrated an initial polymerisation activity of 250 kg(PE)/mol(M)/h/bar. At 70 degrees C, using rac-((3-Et)IndInd(#))(2)ZrCl2, solution phase polymerisation activities were twenty times faster than slurry phase polymerisation using SSMAO-rac-((3-Et)Ind(#))(2)ZrCl2 (1243 and 75 kg(PE)/mol(Zr)/h/bar respectively). (C) 2016 Elsevier Ltd. All rights reserved.