Addition of a second alcohol in magnesium ethoxide synthesis as a way to vary the pore architecture of Ziegler-Natta catalysts

Document Type : Original research

Authors

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

2 School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1211, Japan

Abstract

In Ziegler-Natta olefin polymerization, the pore architecture of catalysts plays a crucial role in catalytic performances and polymer properties. While the type of preparation routes (such as chemical reaction and solution precipitation) greatly affects the catalyst pore architecture as a result of different solidification mechanisms, the modification of the pore architecture within a given route has been hardly achieved. In this study, we propose a simple way to vary the pore architecture of Mg(OEt)2-based Ziegler-Natta catalysts by the addition of a second alcohol. It was found that the addition of a second alcohol during Mg(OEt)2 synthesis affected not only the morphology of Mg(OEt)2 macroparticles but also the shape of building units. The degree of alternation was found to be sensitive to the molecular structure of a second alcohol. Noticeable influences were observed in the case of branched alcohols, where the transformation of plate-like building units to cylindrical ones led to the generation of totally different pore size distributions of resultant catalysts.

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  1. Soga K, Shiono T (1997) Ziegler-Natta catalysts for olefin polymerizations. Prog Polym Sci 22: 1503-1546
  2. Hadian N, Hakim S, Nekoomanesh-Haghighi M, Bahri-Laleh N (2014) Storage time effect on dynamic structure of MgCl2.nEtOH adducts in heterogeneous Ziegler-Natta catalysts. Polyolefins J 1: 33-41
  3. Dil EJ, Pourmahdian S, Vatankhah M, Afshar Taromi F (2010) Effect of dealcoholation of support in MgCl2-supported Ziegler–Natta catalysts on catalyst activity and polypropylene powder morphology. Polym Bull 64: 445-457
  4. Terano M, Murai A, Inoue M, Miyosi K (1987) JP1987158704 (to Toho Catalyst Co. Ltd.)
  5. Nitta T, Liu B, Nakatani H, Terano M (2002) Formation, deactivation and transformation of stereospecific active sites on TiCl4/ dibutylphthalate/Mg(OEt)2 catalyst induced by short time reaction with Al-alkyl cocatalyst. J Mol Catal A: Chem 180: 25-34
  6. Pokasermsong P, Praserthdam P (2009) Comparison of activity of Ziegler-Natta catalysts prepared by recrystallization and chemical reaction methods towards polymerization of ethylene. Eng J 13: 57-64
  7. 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
  8. Zheng X, Pimplapure MS, Weickert G, Loos J (2006) Influence of copolymerization on fragmentation behavior using Ziegler-Natta catalysts. Macromol Rapid Commun 27: 15-20
  9. Dashti A, Ramazani SA, Hiraoka Y, Kim SY, Taniike T, Terano M (2009) Kinetic and morphological study of a magnesium ethoxide based Ziegler–Natta catalyst for propylene polymerization. Polym Int 58: 40-45
  10. Ko YS, Woo SI (2003) Shape and diffusion of the monomer-controlled copolymerization of ethylene and α-olefins over Cp2ZrCl2 confined in the nanospace of the supercage of NaY. J Polym Sci A: Polym Chem 41: 2171-2179
  11. 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
  12. Chammingkwan P, Thang VQ, Terano M, Taniike T (2014) MgO/MgCl2/TiCl4 core-Shell catalyst for establishing structure-performance relationship in Ziegler-Natta olefin polymerization. Top Catal 57: 911-917
  13. Poonpong S, Dwivedi S, Taniike T, Terano M (2014) Structure-performance relationship for dialkyldimethoxysilane as an external donor in stopped-flow propylene polymerization using a Ziegler-Natta catalyst. Macromol Chem Phys 215: 1721-1727
  14. Barrett EP, Joyner LG, Halenda PH (1951) The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms. J Am Chem Soc 73: 373-380
  15. Innes WB (1957) Use of parallel plate model in calculation of pore size distribution. Anal Chem 29: 1069-1073
  16. 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
  17. Sing KSW, Everett DH, Haul RAW, Moscou L, Pierotti RA, Rouquérol J, Siemieniewska T (1985) Physical and biophysical chemistry division commission on colloid and surface chemistry including catalysis. Pure Appl Chem 57: 603-619
  18. Sing KSW (1982) Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (Provisional). Pure Appl Chem 54: 2201-2218
  19. Horvath G, Kawazoe K (1983) Method for the calculation of effective pore size distribution in molecular sieve carbon. J Chem Eng Japan 16: 470-475
  20. Saito A, Foley HC (1995) Argon porosimetry of selected molecular sieves: experiments and examination of the adapted Horvath-Kawazoe model. Microporous Mater 3: 531-542
  21. Taniike T, Chammingkwan P, Thang VQ, Funako T, Terano M (2012) Validation of BET specific surface area for heterogeneous Ziegler-Natta catalysts based on αs-plot. Appl Catal A: Gen 437-438: 24-27