A functionalization of mesoporous materials with organosilane was carried out via a post-synthesis grafting method and (n-BuCp)2ZrCl2/methylaluminoxane (MAO) as subsequently immobilized on the functionalized mesoporous materials for ethylene polymerization. Organosilanes having amine, cyano or imidazoline group such as N-[(3-trimethoxysilyl)propyl]ethylenediamine (2NS), 4-(triethoxysilyl)butyronitrile (1NCy), 1-(3-triethoxysilylpropyl)-2-
imidazoline (2NIm) were used for the surface functionalization of mesoporous materials. In the SBA-15/2NS/(n-BuCp)2ZrCl2 catalyst preparation, the amount of MAO in feed increased with an decrease in the Zr content of the supported catalyst, and Al content in the supported catalyst increased. The ethylene homopolymerization activity of SBA-15/2NS/(n-BuCp)2ZrCl2 dramatically increased as the amount of MAO in feed increased. Furthermore, when the immobilization time was 6 hrs, SBA-15/2NS/(n-BuCp)2ZrCl2 showed the highest activity. The activities of supported 2NS-, 1NCy-, 2NIm-functionalized catalysts decreased in the following order, SBA-15/2NS/ > SBA-15/2NIm/ > SBA-15/1NCy/(n-BuCp)2ZrCl2. 2NS and 2NIm which have two amine groups per silane molecule were shown to interact with (n-BuCp)2ZrCl2 strongly compared to 1NCy which has one amine group. Thus, the activities increased with an increase in the nitrogen and the Zr content of the supported catalysts.
메조포러스 물질의 표면을 post-synthesis grafting method를 통해 표면을 기능화시킨 후 (n-BuCp)2ZrCl2/methylaluminoxane(MAO)를 담지하여 에틸렌 중합을 실시하였다. 아민기와 시안기를 가지는 유기실란 N-[(3-trimethoxysilyl)propyl]ethylenediamine(2NS), 4-(triethoxysilyl)butyronitrile(1NCy), 1-(3-triethoxysilylpropyl)-2-imidazoline(2NIm)는 메조포러스 물질의 표면 기능화에 사용되었다. SBA-15/2NS/(n-BuCp)2ZrCl2촉매 담지시 MAO의 양이 증가할수록 Zr 함량은 감소하였고 Al 함량은 증가하였다. 에틸렌 중합 활성은 MAO의 양이 증가할수록 급격히 증가함을 볼 수 있었다. 담지시간이 6시간일 때 가장 높은 활성을 보였다. 유기실란의 종류에 따른 활성 차이는 SBA-15/2NS/(n-BuCp)2ZrCl2 > SBA-15/2NIm/(n-BuCp)2ZrCl2 > SBA-15/1NCy/(n-BuCp)2ZrCl2 순으로 감소하였다. 아민기를 두 개 갖는 2NS와 2NIm은 아민기를 하나 갖는 1NCy보다 (n-BuCp)2ZrCl2와 더 강하게 상호작용을 한다. 따라서 촉매 내 질소와 Zr함량이 증가할수록 활성은 증가하였다.
Keywords: mesoporous material; surface functionalization; organosilane; metallocene; ethylene polymerization.