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

Iranian Polymer Journal volume 24, pages 621–628 (2015)Cite this article

Abstract

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

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Authors and Affiliations

  1. Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), P.O. Box 45195-1159, Zanjan, Iran

    Zahra Mohamadnia

  2. Department of Chemistry, University of Zanjan, P.O. Box 45195- 313, Zanjan, Iran

    Ebrahim Ahmadi, Atefe Farandpour, Zinat Rezazadeh & Maryam Fallahi

  3. Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965-115, Tehran, Iran

    Mehdi Nekoomanesh Haghighi

Authors
  1. Zahra Mohamadnia
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  2. Ebrahim Ahmadi
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  3. Mehdi Nekoomanesh Haghighi
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  4. Atefe Farandpour
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  5. Zinat Rezazadeh
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  6. Maryam Fallahi
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Correspondence to Zahra Mohamadnia or Ebrahim Ahmadi.

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Mohamadnia, Z., Ahmadi, E., Haghighi, M.N. et al. Preparation of LLDPE through tandem ethylene polymerization using chromium and zirconium catalysts. Iran Polym J 24, 621–628 (2015). https://doi.org/10.1007/s13726-015-0345-0

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  • DOI: https://doi.org/10.1007/s13726-015-0345-0

Keywords

  • Ethylene
  • Trimerization
  • Polymerization
  • 1-Hexene
  • Tandem
  • LLDPE