Magnesium alkoxide precursor to Ziegler-Natta catalyst - emphasis on morphology studies through computer vision approach

Document Type : Original research


Reliance Research & Development Centre, Reliance Corporate Park, Reliance Industries Limited (RIL), Thane Belapur Road, Navi Mumbai-400701, India


MgCl2 supported Ti catalyst is used in commercial propylene polymerization process. Morphology is a key performance determination parameter for polymer resins produced by commercial olefin polymerization process. Higher resin flowability and bulk density (greater than 0.38g/cc) are demonstrated by ‘good’ morphological resins (sphericity close to ‘1’). Polymer resin morphology is controlled by morphology of the catalyst used as well as polymerization conditions. The industrially accepted approaches to control polymer resin morphology are by controlling catalyst morphology through various approaches like pre-polymerization of the catalysts. Morphology of the catalyst is dependent on precursor (support) morphology and process parameters for making the catalyst. In this work, we have developed magnesium alkoxide precursor, a Ziegler-Natta catalyst using the precursor and studied its performance in gas phase propylene polymerization process. Further, morphology of different precursor and catalyst samples is evaluated and correlated it using a “computer vision” based approach. The approach involves modeling the circularity (as an analog of sphericity) of a catalyst and precursor particle. It is observed that the circularity of catalyst particles is lower than that of precursor, due to attrition in the process. It is also reflected in increase in particle size distribution span from 0.83 to 1.32 while synthesis of catalyst from precursor. This approach provides a tool to evaluate and screen the catalysts for using in polymerization.


Main Subjects

  1. Hutchinson RA, Chen CM, Ray WH (1992) Polymerization of olefins through heterogeneous catalysis X: Modeling of particle growth and morphology. J Appl Polym Sci 44: 1389-1414 [CrossRef]
  2. Grof Z, Kosek J, Marek M, Adler PM (2003) Modeling of morphogenesis of polyolefin particles: Catalyst fragmentation. AIChE J 49: 1002-1013 [CrossRef]
  3. Kissin YV, Nowlin TE, Mink RI, Brandoloni AJ (2000) A new cocatalyst for metallocene complexes in olefin polymerization. Macromolecules 33: 4599-4601 [CrossRef]
  4. Chumachenko NN, Zakharov VA, Bukatov GD, Sergeev SA (2014) A study of the formation process of titanium–magnesium catalyst for propylene polymerization. Appl Catal-A 469: 512-516 [CrossRef]
  5. Fisch AG (2023) Fragmentation-oriented design of olefin polymerization catalysts: Support porosity. Catalysts 13: 160-168  [CrossRef]
  6. Hutchinson RA, Ray WH (1991) Polymerization of olefins through heterogeneous catalysis. IX. Experimental study of propylene polymerization over a high activity MgCl2-supported Ti catalyst. J Appl Polym Sci 43: 1271-1285 [CrossRef]
  7. Wristers J (1973) Nascent polypropylene morphology: Polymer fiber. J Polym Sci Pol Phys 11: 1601-1617 [CrossRef]
  8. Chen Y, Liu XG (2005) Modeling mass transport of propylene polymerization on Ziegler–Natta catalyst. Polymer 46: 9434–9442 [CrossRef]
  9. Harshe YM, Utikar RP, Ranade VV (2004) A computational model for predicting particle size distribution and performance of fluidized bed polypropylene reactor. Chem Eng Sci 59: 5145-5156 [CrossRef]
  10. Spitz R, Bobichon C, Guyot A (1989) Synthesis of polypropylene with improved MgCl2-supported Ziegler-Natta catalysts, including silane compounds as external bases. Macromol Chem Phys 190: 707–716 [CrossRef]
  11. Guastalla G, Giannini U (1983) The influence of hydrogen on the polymerization of propylene and ethylene with an MgCl2 supported catalyst. Makromol Chem Rapid Commun 4: 519-527 [CrossRef]
  12. Samson JJC, Middelkoop BV, Weickert G, Westerterp KR (1999) Gas phase polymerization of propylene with a highly active Ziegler-Natta catalyst. AIChE J 45: 1548-1558 [CrossRef]
  13. Cancelas AJ, Monteil V, McKenna TFL (2016) Influence of activation conditions on the gas phase polymerisation of propylene. Macromol Symp 360: 133-141 [CrossRef]
  14. Liu B, Matsuoka H, Terano M (2001) Stopped-flow techniques in Ziegler-catalysis. Macromol Rapid Commun 22: 1–24 [CrossRef]
  15. Martino AD, Broyer JP, Schweich D, Bellefon CD, Weickert G, McKenna TFL (2007) Design and implementation of a novel quench flow reactor for the study of nascent olefin polymerisation. Macromol React Eng 1: 284-297  [CrossRef]
  16. Poonpong S, Dwivedi S, Taniike T, Terano M (2014) Structure-performance relationship for di-alkyl dimethoxy silane as external donor in stopped-flow propylene polymerization using Ziegler-Natta catalyst. Macromol Chem Phys 215: 1721-1727 [CrossRef]
  17. Olalla B, Broyer JP, McKenna TFL (2008) Heat transfer and nascent polymerisation of olefins on supported catalysts. Macromol Symp 271: 1–7 [CrossRef]
  18. McKenna TFL, Tioni E, Ranieri MM, Alizadeh A, Boisson C, Monteil,V (2013) Catalytic olefin polymerisation at short times: Studies using specially adapted reactors. Can J Chem Eng 91: 669-686 [CrossRef]
  19. Mori H, Ohnishi K, Terano M (1998) Multiplicity of molecular weight distribution of polyethene produced with modified-polypropene-supported Ziegler catalyst systems. Macromol Chem Phys 199: 393-399 [CrossRef]
  20. Arabi H, Abedini H, Dolatshahi H, Nejabat GR (2013) Ziegler-Natta catalyst preparation process: Influential parameters on particles morphology and activity of catalyst in propylene polymerization. Iran J Polym Sci Technol 26: 209-219 [CrossRef]
  21. Chumachenko NN, Vladimir A, Zakharov SA, Cherepanova SV (2017) Effect of the synthesis conditions of titanium-magnesium catalysts on the composition, structure and performance in propylene polymerization. Polyolefin J 4: 111-122 [CrossRef]
  22. Redzic E, Garoff T, Mardare CC, List M, Hesser G, Mayrhofer L, Hassel AW, Paulik C (2016) Heterogeneous Ziegler–Natta catalysts with various sizes of MgCl2 crystallites: synthesis and characterization. Iran Polym J 25: 321-337 [CrossRef]
  23. Alizadeh A, McKenna TFL (2018) Particle growth during the polymerization of olefins on supported catalysts. Part 2: Current experimental understanding and modeling progresses on particle fragmentation, growth, and morphology development. Macromol React Eng 12: 1700027 [CrossRef]
  24. Ermakov YI, Zakharov VA (1972) Determination of the number of active centres and growth rate constants in the catalytic polymerisation of α-alkenes. Russ Chem Rev 41: 203-215 [CrossRef]
  25. Nagel EJ, Kirillov VA, Ray WH (1980) Prediction of molecular weight distributions for high-density polyolefins. Ind Eng Chem Prod Res Dev 19: 372–379 [CrossRef]
  26. Trivedi PM, Gupta VK (2021) Progress in MgCl2 supported Ziegler-Natta catalyzed polyolefin products and applications. J Poly Res 45: 02412-5 [CrossRef]
  27. Makwana U, Naik DG, Singh G, Patel V, Patil HR, Gupta VK (2009) Nature of phthalates as internal donors in high performance MgCl2 supported titanium catalyst. Catal Lett 131: 624-631 [CrossRef]
  28. Makwana UC, Singala KJ, Patankar RB, Singh SC, Gupta VK (2012) Propylene polymerization using supported Ziegler-Natta catalyst systems with mixed donors. J Appl Polym Sci 125: 896–901 [CrossRef]
  29. Sharma A, Singh S, Singh G, Gupta VK (2011) Polypropylene resin flowability improvement through catalyst morphology. Polym Plast Tech Eng 50: 418–422 [CrossRef]
  30. Gupta VK, Singh S, Makwana UC, Joseph J, Singala KJ, Rajesh S, Patel V, Yadav MK, Singh G (2014) Spheroidal particles for olefin polymerization catalyst. US8633124B2
  31. Gupta VK, Patil HR, Naik DG, Kaur S, Singh G, Vyas PB (2011) Catalyst system for polymerization of olefins. US8043990 B2
  32. Gupta VK, Patil HR, Naik DG (2014) Propylene polymerization catalyst system. US8853118B2
  33. Taniike T, Funako T, Terano M (2014) Multilateral characterization for industrial Ziegler–Natta catalysts toward elucidation of structure–performance relationship. J Catal 311: 33-40 [CrossRef]
  34. Zorve P, Linnolahti M (2018) Adsorption of titanium tetrachloride on magnesium dichloride clusters. ACS Omega 3: 9921-9928 [CrossRef]
  35. Abboud M, Denifl P, Reichert KH (2005) Study of the morphology and kinetics of novel Ziegler-Natta catalysts for propylene polymerization. J Appl Polym Sci 98: 2191-2200 [CrossRef]
  36. Klaue A, Kruck M, Friederichs N, Bertola F, Wu H, Morbidelli M (2019) Insight into the synthesis process of an industrial Ziegler-Natta catalyst. Ind Eng Chem Res 58: 886−896 [CrossRef]
  37. Zohuri G, Bonakdar MA, Damavandi S, Eftekhar M, Askari M, Ahmadjo S (2009) Preparation of ultra high molecular weight polyethylene using bi-supported SiO2/MgCl2 (spherical)/TiCl4 Catalyst: A Morphological Study. Iran Polym J 18: 593-600 [CrossRef]
  38. Zohuri GH, Askari M, Ahmadjo S, Damavandi S, Eftekhar M, Bonakdar MA (2010) Preparation of ultra-high-molecular-weight polyethylene and its morphological study with a heterogeneous Ziegler–Natta catalyst. J Appl Polym Sci 118: 3333–3339 [CrossRef]
  39. Jamjah R, Zohuri GH, Vaezi J, Ahmadjo S, Nekomanesh M, Pouryari M (2006) Morphological study of spherical MgCl2.nEtOH supported TiCl4 Ziegler-Natta catalyst for polymerization of ethylene. J Apply Polym Sci 101: 3829-3834 [CrossRef]
  40. Munoz-Escalona A, Alarcon C, Albornoz LA, Fuentes A, Sequera JA (1988) Morphological characterization of Ziegler-Natta catalysts and nascent polymers. In: Transition metals and organometallics as catalysts for olefin polymerization, eds: Kaminsky W, Sinn H, Springer, Berlin, Heidelberg