Polymerization of olefins with single-site catalyst anchored on amine-functionalized surface of SBA-15

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• 作者：Jeong Suk Lee^a ; Jin-Heong Yim^b ; Jong-Ki Jeon^a ; Young Soo Ko^a ; ^{ysko@kongju.ac.kr}
• 关键词：SBA-15 ; Metallocene immobilization ; Organosilane ; Surface functionalization ; Ethylene polymerization
• 刊名：Catalysis Today
• 出版年：2012
• 期刊代码：13_09205861
• 类别：ce
• 出版时间：20 May, 2012
• 卷：185
• 期：1
• 页码：175-182
• 文件大小：1420 K

摘要

Mesoporous silica SBA-15 functionalized with amine or nitrile group have been synthesized and (n-BuCp)₂ZrCl₂ and methylaluminoxane (MAO) were subsequently immobilized on the functionalized SBA-15 for the further evaluation as a catalyst of ethylene polymerization. Five silanes such as 3-aminopropyltrimethoxysilane(1NS), N-[(3-trimethoxysilyl)propyl]ethylenediamine(2NS), N¹-[3-(trimethoxysilyl)propyl]diethylenetriamine(3NS), and 4-(triethoxysilyl)butyronitrile(1NCy), 1-(3-triethoxysilylpropyl)-2-imidazoline(2NIm) were compared as functional groups for the immobilization (n-BuCp)₂ZrCl₂ and methylaluminoxane (MAO). Zr contents in the final supported catalysts were observed to be strongly dependent on the nitrogen content on the surface of functionalized SBA-15, indicating the more Zr could be immobilized due to the interaction between (n-BuCp)₂ZrCl₂ and amine or nitrile groups presented on the surface of SBA-15. 2NIm, 2NS and 3NS were shown to interact with (n-BuCp)₂ZrCl₂ strongly compared to 1NCy and 1NS due to larger number of amine groups and formation of stable active species. The ethylene homo- and copolymerization activities of (n-BuCp)₂ZrCl₂ supported on the amine or nitrile-functionalized SBA-15 were increased with an increase in the nitrogen and Zr content in the supported catalyst. The electron-donating effect of the amine or nitrile surface group on the surface toward the (n-BuCp)₂ZrCl₂ was expected to be a significant parameter in consideration of the higher activity of ethylene homopolymerization and ethylene-1-hexene copolymerization. SBA-15/1NCy/(n-BuCp)₂ZrCl₂ also showed different chemical compositional distribution of ethylene-1-hexene copolymer compared to the others, meaning change in nature of active species. It would result from different electric environment of nitrile group from amine one. It also revealed that the resulting polymer particle prepared supported (n-BuCp)₂ZrCl₂ on the amine or nitrile-functionalized SBA-15 was more regular and larger in particle size than that of no functionalized SBA-15.