A practical criterion for synthesizing ethylen-1-butene copolymer in powder form in slurry polymerization with a Ziegler-Natta catalyst and predicting its incorporated 1-butene

Document Type : Original research

Authors

1 Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14975/112, Tehran, Iran

2 Department of Plastics, Faculty of Polymer Processing, Iran Polymer and Petrochemical Institute, PO Box 14965/115, Tehran, Iran

Abstract

The concentration of ethylene and 1-butene in n-hexane as polymerization media was calculated at five different pressure levels (4, 6, 8, 10, and 12 bar) and four different 1-butene concentrations (0.13, 0.26, 0.39, and 0.52 mol/L) in n-hexane at T= 80°C using the Peng-Robinson thermodynamic equation of state. Some combinations of conditions were selected to perform the copolymerization reaction in the presence of an industrial TiCl4/MgCl2 Ziegler-Natta catalyst. The forms of the synthesized products were visually and qualitatively classified as either powder or sticky. The percentage of incorporated 1-butene comonomer into the polyethylene chains was analyzed using calibrated FTIR tests. It was shown that for ethylene/1-butene concentration ratios (β) in n-hexane above approximately 1.80, the product forms as a powder. For values below 1.30 threshold, the product was sticky. Thus, this ratio could be used as a criterion for selecting the proper combination of copolymerization pressure and 1-butene concentration when aiming to achieve a powdered form of the product. It was shown that β has a strong correlation with the weight percentage of 1-butene in the final LLDPE polymer. Therefore it can be used as an accurate prediction for wt.% of incorporated 1-butene into the LLDPE chain within the studied concentration ranges with the specific catalyst system utilized.

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References

  1. Hassanian-Moghaddam D, Mortazavi SMM, Ahmadjo S, Doveirjavi M, Rahmati A, Ahmadi M (2022) Resolving long-chain branch formation in tandem catalytic coordinative chain transfer polymerization of ethylene via thermal analysis. J Polym Res 29: 3
  2. Hassanian-Moghaddam D, Maddah Y, Ahmadjo S, Mortazavi SMM, Sharif F, Ahmadi M (2021) Mechanistic study on the metallocene-based tandem catalytic coordinative chain transfer polymerization for the synthesis of highly branched polyolefins. Eur Polym J 152: 110454
  3. Ebrahimi A, Ahmadjo S, Mohammadi M, Mortazavi MM, Ahmadi M (2019) Interplay of reversible chain transfer and comonomers incorporation reactions in coordination copolymerization of ethylene/1-hexane. Polyolefins J 6: 1-24
  4. Masoory M, Ahmadjo S, Mortazavi MM, Vakili M (2017) Copolymerization of ethylene α-olefin using MgCl2-ethanol adduct catalysts. J Macromol Sci A: Pure Appl Chem 54: 140-144
  5. Mortazavi SMM, Ahmadjo S, Omidvar M, Zamani MR, Fallahnezhad R (2021) Investigation into the effect of branch length of polyolefin and its statistical distribution on the flow improving performance. J Polym Res 28: 24
  6. An M, Cui B, Duan X (2022) Preparation and applications of linear low-density polyethylene. J Phys Conf Ser 2229: 012009
  7. Białek M, Czaja K (2000) The effect of the comonomer on the copolymerization of ethylene with long chain α-olefins using Ziegler–Natta catalysts supported on MgCl2 (THF)2. Polymer 41: 7899–7904
  8. Galli P, Vecellio G (2004) Polyolefins: The most promising large-volume materials for the 21st J Polym Sci Pol Chem 42: 396 – 415
  9. Kissin YV, Rishina LA (2008) Kinetics of propylene and ethylene polymerization reactions with heterogeneous Ziegler-Natta catalysts: Recent results. Polym Sci Ser A+ 50: 1101-1121
  10. Simpson DM, Vaughan GA (2002) Ethylene polymers, LLDPE. In: Encyclopedia of polymer science and technology. John Wiley, New York, 441-482
  11. Fontes CH, Mendes MJ (2005) Analysis of an industrial continuous slurry reactor for ethylene– butene copolymerization. Polymer 46: 2922-2932
  12. James C, Armstrong M, Biaglow A (2020) Consistency of thermodynamic properties from CHEMCAD process simulations. Chem Data Collect 30: 100371-100379
  13. Peng D-Y, Robinson DB (1976) A new two-constant equation of state. Ind Eng Chem Fundam 15: 59-64
  14. Peng DY, Robinson DB (1978) The characterization of the heptanes and heavier fractions for the GPA Peng-Robinson programs. Gas processors association, Tulsa, Okla
  15. Privat R, Jaubert J-N (2012) Thermodynamic models for the prediction of petroleum-fluid phase behaviour. In: Crude oil emulsions-composition stability and characterization. Ed: Abdul-Raouf E-S, InTech, Rijeka, Croatia, 71–106
  16. Abudour AM, Mohammad SA, Robinson RL, Gasem KAM (2012). Volume-translated Peng–Robinson equation of state for saturated and single-phase liquid densities. Fluid Phase Equilibria 335: 74-87
  17. Atiqullah M, Hammawa H, Hamid H (1998) Modeling the solubility of ethylene and propylene in a typical polymerization diluent: Some selected situations. Eur Polym J 34: 1511-1520
  18. Dashti A, Mazloumi SH, Akbari A, Ahadiyan HR, Emami AR (2016) Solubility of ethane in n-hexane and n-heptane as common slurry-phase polymerization solvents: Experimental measurement and modeling. J Chem Eng Data 61: 693-697
  19. Li J, Tekie Z, Mizan TI, Morsi BI, Maier EE, Singh CPP (1996) Gas-liquid mass transfer in a slurry reactor operating under olefinic polymerization process conditions. Chem Eng Sci 51: 549-559
  20. Nagy I, Krenz RA, Heidemann RA, de Loos TW (2005) Vapor-liquid equilibrium data for the ethylene+ hexane System. J Chem Eng Data 50: 1492-1495
  21. Young AF, Pessoa FLP, Ahón VRR (2016) Comparison of 20 alpha functions applied in the Peng–Robinson equation of state for vapor pressure estimation. Ind Eng Chem Res 55: 6506-6516
  22. Soares JBP, McKenna TFL (2012) Polyolefin reaction engineering, John Wiley,7-8
Polyolefins Journal
Volume 10, Issue 4 - Serial Number 22
November 2023
Pages 243-251

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History

  • Receive Date: 31 August 2023
  • Revise Date: 18 October 2023
  • Accept Date: 28 October 2023
  • First Publish Date: 28 October 2023

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