Probing into morphology evolution of magnesium ethoxide particles as precursor of Ziegler-Natta catalysts

Document Type : Original research


School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan


Mg(OEt)2 with spherical morphology is one of the most important precursors for the preparation of industrial Ziegler-Natta catalysts. In the present article, morphology evolution of Mg(OEt)2 particles is studied in the course of the synthesis. The morphology of Mg(OEt)2 particles is observed throughout the process by SEM. The results show that Mg(OEt)2 particles are formed through i) seed generation on Mg surfaces, ii) seed growth and isolation as independent particles, and iii) further growth and shaping into smoother and more spherical particles. The size of Mg sources greatly affects the rates of these processes to different extents. A larger size of Mg leads to slower seed formation and growth, and detachment of clustered seeds, making the final particles larger and less spherical, respectively. The crystal growth of Mg(OEt)2 is also affected by the size of Mg sources, which in turn differentiates the pore size distribution to affect the catalyst composition and performance.


Main Subjects

  1. Pater JTM,Weickert G, Van Swaaij WPM (2003) Polymerization of liquid propylene with a fourth-generation Ziegler–Natta catalyst: Influence of temperature, hydrogen, monomer concentration, and prepolymerization method on powder morphology. J Appl Polym Sci 87: 1421-1435
  2. Galli P, Barbè PC, Noristi L (1984) High yield catalysts in olefin polymerization. General outlook on theoretical aspects and industrial uses. Angew Makromol Chem 120: 73-90
  3. Ye ZY, Wang L, Feng LF, Gu XP, Chen HH, Zhang PY, Pan J, Jiang S, Feng LX (2002) Novel spherical Ziegler–Natta catalyst for polymerization and copolymerization. I. Spherical MgCl2 support. J Polym Sci, Part A: Polym Chem 40: 3112-3119
  4. Miya S, Tachibana M, KarasawaY (1992) Process for producing a catalyst for olefin polymerization. US Patent 5100844
  5. Kioka M, Kitani H, Kashiwa N (1982) Process for producing olefin polymers or copolymers. US Patent 4330649
  6. Batinas-Geurts AA, Friederichs NH, Schoffelen T, Zuidema E (2014) Catalyst system for the production of ultra-high molecular weight polyethylene. US Patent 20140296454
  7. 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
  8. Joseph J, Singh SC, Gupta VK (2009) Morphology controlled magnesium ethoxide: Influence of reaction parameters and magnesium characteristics. Part Sci Technol 27: 528-541
  9. Gupta V, Singh S, Makwana U, Joseph J, Singala K, Rajesh S, Patel V, Yadav M, Singh G (2014) Spheroidal particles for olefin polymerization catalyst. US Patent 8633124B2
  10. Nomura H, Kurihara N, Higuchi K (1991) Synthesis of spherical magnesium alcoholate having narrow particle size distribution. JP Patent 199174341
  11. Yamanaka A, Kumai H, Suyama M (2007) Dialkoxymagnesium granular material and synthesis and use thereof. JP Patent 2007297371
  12. Yamanaka A, Kumai H, Suyama M (2014) Dialkoxymagnesium granules and method for their synthesis. US Patent 8632882
  13. Tanase S, Katayama K, Inasawa S, Okada F, Yamaguchi Y, Konakazawa T, Junke T, Ishihara N (2008) Particle growth of magnesium alkoxide as a carrier material for polypropylene polymerization catalyst. Appl Catal A: Gen 350: 197-206
  14. Tanase S, Katayama K, Inasawa S, Okada F, Yamaguchi Y, Sadashima T, Yabunouchi N, Konakazawa T, Junke T, Ishihara N (2008) New synthesis method using magnesium alkoxides as carrier materials for Ziegler-Natta catalysts with spherical morphology. Macromol React Eng 2: 233-239
  15. Funako T, Chammingkwan P, Taniike T, Terano M (2015) Alternation of pore architecture of Ziegler–Natta catalysts through modification of magnesium ethoxide. Macromol React Eng. DOI: 10.1002/mren.201400074
  16. Funako T, Chammingkwan P, Taniike T, Terano M (2015) Addition of a second alcohol in magnesium ethoxide synthesis as a way to vary the pore architecture of Ziegler-Natta catalysts. Polyolefins J 2: 65-71
  17. Terano M, Murai A, Inoue M, Miyoshi K (1987) Catalyst for polymerization of olefin. JP Patent S62158704
  18. Scherrer P(1918) Determination of the size and internalstructure of colloidal particles using X-rays. Math-Phys Kl 2: 98-100
  19. Innes WB (1957) Use of parallel plate model in calculation of pore size distribution. Anal Chem 29: 1069-1073
  20. Turova NY, Turevskaya EP (1972) Alkoxymagnesium halides. J Organomet Chem 42: 9-17
  21. Snyder RC, Doherty MF (2007) Faceted crystal shape evolution during dissolution or growth. AIChE J 53: 1337-1348
  22. Leofanti G, Padovan M, Tozzola G, Venturelli B (1998) Surface area and pore texture of catalysts. Catal Today 41: 207-219
  23. Potapov AG, Bukatov GD, Zakharov VA (2009) DRIFTS study of the interaction of the AlEt3 cocatalyst with the internal donor ethyl benzoate in supported Ziegler–Natta catalysts. J Mol Catal A: Chem 301: 18-23