Document Type : Original research
Authors
State Key Laboratory of Chemical Engineering,East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
Abstract
Vanadium-modified (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta catalysts were prepared through co-impregnation of water-soluble magnesium and vanadium salts under different pH values. Several key factors such as pH value of co-impregnation solution during catalyst preparation, catalyst performances including catalytic activity, ethylene/1-hexene copolymerization and hydrogen response were investigated. It is found that the components, structures and performance of the catalysts are obviously affected by changing the pH value (pH=5, 7 and 9) of co-impregnation solution. An appropriate pH value (pH=7) can maximize catalytic activity and hydrogen response, while lower pH value (pH=5) is beneficial to the 1-hexene incorporation. The GPC results show that the polymers obtained have high average molecular weight.
Keywords
Main Subjects
- Kashiwa N (2004) The discovery and progress of MgCl2 -supported TiCl4 catalysts. J Polym Sci Pol Chem 42: 1-8
- Kashiwa N, Yoshitake J (1984) The influence of the valence state of titanium in MgCl2 –supported titanium catalysts on olefin polymerization. Makromol Chem 185: 1133-1138
- Kashiwa N, Fujimura H, Tokuzumi Y (1968) Process for the polymerization and/ or copolymerization of olefins with the use of Ziegler-type catalysts supported on carrier. JP Patent 1,031,698
- Galli P, Luciani L, Cecchin G (1981) Advances in the polymerization of polyolefins with coordination catalysts. Die Angew Makromol Chem 94: 63-89
- Mayr A, Galli P, Susa E, Drusco GD, Giachetti E (1968) Polymerization of olefins. GB Patent 1,286,867
- Böhm LL (2003) The ethylene polymerization with Ziegler catalysts: Fifty years after the discovery. Angew Chem Int Ed 42: 5010-5030
- Stevens J, George M (1974) Catalysts and process for the polymerization of olefins. US Patent 3,787,384
- Matta A, Zeng Y, Taniike T, Terano M (2012) Vanadium-modified bimetallic Phillips catalyst with high branching ability for ethylene polymerization. Macromol React Eng 6: 346-350
- Wagner BE, Gokek GL, Karol FJ (1981) Process for the preparation of high density ethylene polymers in fluid bed reactor. US Patent 4,303,771
- Chamla C, Daire E (1991) Supported polyolefin catalyst for the (co-)polymerization of ethylene in gas phase. EP Patent 0,453,088
- Wang J, Cheng R, He X, Liu Z, Tian Z, Liu B (2015) A novel (SiO2 /MgO/MgCl2 )•TiClx ZieglerNatta catalyst for ethylene and ethylene/1-hexene polymerization. Macromol Chem Phys 216: 1472-1482
- Hsieh JT, Pruden AL (1995) Mixed chromium catalyst, and alkene and alkyl aluminum hydridemodified Ziegler catalyst for multimodal HDPE. US Patent 5,408,015
- Hsieh JT (1994) Mixed Ziegler and chromium catalyst and process for preparing a broad molecular weight distribution HDPE. US Patent 5,330,950
- Ciaccia E, Vittorias I, Mihan S, Lukesova L, Lilge D, Salinas MH, Meier G, Mannebach G (2011) Process for the polymerization of ethylene, and ethylene polymers having broad molecular weight distribution and long-chain branching. US Patent 0,251,360
- Bazvand R, Bahri-Laleh N, Nekoomanesh M, Abedini H (2015) Highly efficient FeCl3 doped Mg(OEt)2 /TiCl4 -based Ziegler–Natta catalysts for ethylene polymerization. Des Monomers Polym 18: 599-610
- Garoff T, Leinonen T (1996) Mn doping of the Ziegler-Natta PP catalyst support material. J Mol Catal A-Chem 104: 205-212
- Fregonese D, Bresadola S (1999) Catalytic systems supported on MgCl2 doped with ZnCl2 for olefin polymerization. J Mol Catal A-Chem 145: 265-271
- Phiwkliang W, Jongsomjit B, Praserthdam P (2014) Synergistic effects of the ZnCl2 -SiCl4 modified TiCl4/MgCl2/THF catalytic system on ethylene/1-hexene and ethylene/1-octene copolymerizations. Chinese J Polym Sci 32: 84-91
- Chen Y, Fan Z (2006) Ethylene/1-hexene copolymerization with TiCl4/MgCl2/AlCl3catalyst in the presence of hydrogen. Eur Polym J 42: 2441-2449
- Chen Y, Fan Z, Liao J, Liao S (2006) Molecular weight distribution of polyethylene catalyzed by Ziegler–Natta catalyst supported on MgCl2 doped with AlCl3. J Appl Polym Sci 102: 1768-1772
- Wang J, Cheng R, He X, Liu Z, Zhao N, Liu B (2015) Vanadium modification effects on the (SiO2 /MgO/MgCl2)•TiClx Ziegler-Natta polyethylene catalyst. Macromol React Eng 10: 246-260
- Wang J, Cheng R, He X, Liu Z, Zhao N, Liu B (2015) Introduction of chromium species into the (SiO2 /MgO/MgCl2 )•TiClx Ziegler–Natta catalyst for better catalytic performance. J Organomet Chem: 299-310
- Fu T, Cheng R, He X, Liu Z, Tian Z, Liu B (2016)Modification of the (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta polyethylene catalysts using third metal elements. Chinese J Polym Sci 35: 1-13
- Wunderlich B, Czornyj G (1977) A study of equilibrium melting of polyethylene. Macromolecules 10: 906-913
- Seger MR, Maciel GE (2004) Quantitative 13C NMR analysis of sequence distributions in poly(ethylene-co-1-hexene). Anal Chem 76: 5734-5747
- Huang F, Wang J, Cheng R, He X, Liu Z, Zhao N, Liu B (2016) Optimization of the preparation temperature for the novel (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta polyethylene catalyst. Macromol React Eng 10: 567-576
- Fu T, Cheng R, He X, Liu Z, Tian Z, Liu B (2016)Imido-modified SiO2 -supported Ti/Mg ZieglerNatta catalysts for ethylene polymerization and ethylene/1-hexene copolymerization. Polyolefins J 3: 103-117
- Gao J, Guo J, Liang D, Hou Z, Fei J, Zheng X (2008) Production of syngas via autothermal reforming of methane in a fluidized-bed reactor over the combined CeO2 –ZrO2/SiO2 supported Ni catalysts. Int J Hydrogen Energy 33: 5493-5500
- Andoni A, Chadwick JC, Niemantsverdriet HJW, Thüne PC (2007) A preparation method for welldefined crystallites of MgCl2 -supported ZieglerNatta catalysts and their observation by AFM and SEM. Macromol Rapid Commun 28: 1466-1471
- Senso N (2010) The influence of mixed activators on ethylene polymerization and ethylene/1- hexene copolymerization with silica-supported Ziegler-Natta catalyst. Molecules 15: 9323-9339
- Fan Z, Zhang L, Xia S, Fu Z (2011) Effects of ethylene as comonomer on the active center distribution of 1-hexene polymerization with MgCl2-supported Ziegler–Natta catalysts. J Mol Catal A-Chem 351: 93-99
- Kissin YV, Rishina LA (2008) Kinetics of propylene and ethylene polymerization reactions with heterogeneous Ziegler-Natta catalysts: Recent results. Polymer Sci A 50: 1101-1121
- Hassan Nejad M, Ferrari P, Pennini G, Cecchin G (2008) Ethylene homo- and copolymerization over MgCl2 -TiCl4 catalysts: Polymerization kinetics and polymer particle morphology. J Appl Polym Sci 108: 3388-3402
- Kim JH, Jeong YT, Woo SI (1994)Copolymerization of ethylene and 1-butene with highly active TiCl4 /THF/MgCl2, TiCl4/THF/MgCl2/SiO2, and TiCl31/3AlCl3 catalysts. J Polym Sci Pol Chem 32: 2979-2987
- Yang H, Huang B, Fu Z, Fan Z (2015) Ethylene/1-hexene copolymerization with supported Ziegler–Natta catalysts prepared by immobilizing TiCl3 (OAr) onto MgCl2. J Appl Polym Sci 132: DOI: 10.1002/app.41329
- Novokshonova LA,Zakharov VA (2013)Kinetics of olefin polymerization and activesites of heterogeneous Ziegler-Natta catalysts. In: Polyolefins: 50 years after Ziegler and Natta I: Polyethylene and polypropylene, Ed. W Kaminsky. Springer, Berlin, 99-134
- Hindryckx F, Dubois P, Jérôme R, Mattib MG (1998) Ethylene polymerisation by a high activity MgCl2 supported Ti catalyst in the presence of hydrogen and/or 1-octene. Polymer 39: 621-629
- Marques MMV, Nunes CP, Tait PJT, Dias AR (1993) Polymerization of ethylene using a highactivityZiegler–Natta catalyst. I. Kinetic studies. J Polym Sci Pol Chem 31: 209-218
- 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