Experimental and Computational Approaches on the Isospecific Role of Monoester-Type Internal Electron Donor for TiCl4/MgCl2 Ziegler-Natta Catalysts |
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| Authors: | Boping Liu Ruihua Cheng Zhen Liu Pengyuan Qiu Shiliang Zhang Toshiaki Taniike Minoru Terano Kunihiko Tashino Takashi Fujita |
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| Institution: | 1. State Key Lab of Chemical Engineering, East China University of Science and Technology, Mei Long Road 130, Shanghai, P.C. 200237, P.R. China;2. School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi, Ishikawa, 923-1292, Japan;3. R&D Section, Toho Catalyst Co., LTD., 3-3-5 Chigasaki-City, Kanagawa-Pref. 253-0041, Japan |
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| Abstract: | In this work, a combination of experimental and computational approaches on the isospecific role of monoester-type internal electron donors (ED) such as phenylpropionate (PhP), ethylheptanoate (EH), methylbenzoate (MB), ethylbenzoate (EB) for TiCl4/ED/MgCl2 Ziegler-Natta catalysts had been performed. The propylene polymerization results revealed that the isospecificity of catalysts increases in the following order: PhP < EH < MB < EB. The subsequent molecular modeling on the electronic properties of the donors and two kinds of cluster model catalysts: TiCl4/ED/MgCl2 and TiCl4/ED/(MgCl2)4 based on density functional theory (DFT) method was carried out. Two kinds of ED coordination on MgCl2 clusters through either ?O or ? O? within the monoester-type ED had been disclosed. A perfect correlation between the dipole moment of ED, the coordination bond length of ?O … Mg, the competitive coordination from ? O? with Mg ion and the isospecificity of the catalysts had been established. |
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| Keywords: | internal electron donor molecular modeling polypropylene (PP) Ziegler-Natta polymerization |
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