Supporting of nickel(II) acenaphthenediimine with free amino group for ethylene polymerization

Abstract

Bis (4-(4-amino-3, 5-diethylbenzyl)-2, 6-diethylphenylimino) acenaphthene] dichloronickel (NiLCl₂) was prepared and supported on SiO₂ modified by methyl trichlorsilane(S-1) and on SiO₂-MgCl₂/TiCl₄ (S-2) respectively. Two supported catalysts S-1 and S-2 used as catalysts for ethylene polymerization were studied and the influences of various polymerization conditions, including the polymerization temperature, cocatalysts, Al/Ni molar ratio on the catalytic activity, branching degree and branch length of PE were also investigated. The experimental results show that the supported catalysts exhibit higher catalytic activity for ethylene polymerization, the highest catalytic activity of S-1 using AlEt₂Cl as cocatalyst at 50°C, reaching 5.8×10⁵gPE/molNi··h, and needed lower Al/Ni molar ratio compared to homogeneous analogue.

Keywords

nickel diimine complex / supported catalyst / branched polyethylene / diethylaluminium chloride

References

[1] Johnston L. K., Killian C. M., Brookhart M. New Pd(II)- and Ni(II)-base Catalystss for Polymerization of Ethylene and α-Olefin[J]. J. Am. Chem. Soc., 1995, 117(23): 6414-6415.

[2] Simon L. C., Patel H., Soares J. B. P., de Souza R. F. Polyethylene Made with In Situ Supported Ni-Diimine/SMAO: Replication Phenomenon and Effect of Polymerization Conditions on Polymer Microstructure and Morphology[J]. Macromol. Chem. Phys., 2001, 202(17): 3237-3247.

[3] Ye Z., Alsyouri H., Zhu S., Lin Y. S. Catalyst Impregnation and Ethylene Polymerization with Mesoporous Particle Supported Nickel-diimine Catalyst[J]. Polymer, 2003, 44(4): 969-980.

[4] Killian C M, Lavoie G G, MacKenzie P B, et al. Supported Group 8–10 Transition Metal Olefin polymerization Catalysts[P]. EP Patent WO9962968(1999, 12, 9)

[5] Canich J A M, Gindelberger D E, Matsunaga P T, et al. Supported Late Transition Metal Catalyst Systems[P]. EP Patent WO9748736(1997, 12, 24)

[6] Pflugl P. P., Brookhart M. Highly Active Supported Nickel Diimine Catalysts for Polymerization of Ethylene[J]. Macromolecules, 2002, 35(16): 6074-6076.

[7] Peruch F., Cramail H., Deffieux A. Kinetic and UV-Visible Spectroscopic Studies of Hex-1-ene Polymerization Initiated by an α-Diimine-[N,N] Nickel Dibromide/MAO Catalytic System[J]. Macromolecules, 1999, 32(24): 7977-7983.

[8] Jiang H. L., Hu Y. J., Wang H. H. (α-Diimine)Nickel Covalently Supported Catalyst for Ethylene Polymerization[J]. Petrochemical Technology, 2006, 35(4): 329-333.

[9] Xue X. H., Yang X., Xiao Y. Z., . Ethylene Polymerization Using Nickel α-diimine Complex Supported on SiO₂/MgCl₂ Bisupport [J]. Polymer, 2004, 45(9): 2877-2882.

[10] Zhang D. P., Zhao W., Xu X. X., . Synthesis and Supporting of Non-Metallocene Schift Base Ti Complexes TiCl₃ and Study of Olefin Polymerization[J]. Petrochemical Technology, 2003, 32(6): 41-44.

[11] FAN Xin-gong. Study on Polymerization of Ethylene, 4-Vinylpyridine and Acrylonitrile with Early and Lated Transitional Metals[D]. Sun Yat-sen University, 2003

[12] Usami T., Takayama S. Fine-Branching Structure in High-Pressure,Low-Density Polyethylenes by 51.10-MHz ¹³C NMR Analysis[J]. Macromolecules, 1984, 17(9): 1756

[13] Killian C. M., Johnson L. K., Brookhart M. Preparation of Linear α-Olefins Using Cationic Nickel (II) α-Diimine Catalysts[J]. Organometallics, 1997, 16(10): 2005-2007.

[14] Linderman L. P., Adams J. Q. Carbon-13 Nuclear Magnetic Resonance Spectrometry[J]. Anal. Chem., 1971, 43(10): 1245-1252.