Preparation of LLDPE through tandem ethylene polymerization using chromium and zirconium catalysts

摘要: The effective tandem catalysis systems including the trimerization catalyst of CrCl3/SNS [SNS = bis-(2-pentylsulfanyl-ethyl)-amine] and copolymerization rac-ethylene bis(indenyl) zirconium (IV) dichloride have been introduced. was synthesized via reaction between CrCl3(THF)3 precursor SNS as efficient ligand at room temperature. An ethylene 90 °C 23 bar ethylene, using complex activated by 700 equivalents methylaluminoxane, afforded 99.9 % 1-C6. Only 0.10 % PE produced. Effect different parameters such pressure Cr/Zr ratio investigated during polymerization. Successive increases in amount yielded a series copolymer samples with decreased T m X c. butyl branches produced polymer were identified 13C NMR analysis. Data from dynamic mechanical thermal analysis indicated formation various polymeric materials branches, which their stiffness varied according to used polymerization reaction.