摘要
高活性烯烃聚合催化剂的制备方法与有关技术近年来有很大发展.当前较好的是三井TK催化剂体系.其主要特点之一是将MgCl_2与醇(主要是大于C_6的异构醇)在烃类溶剂中反应生成MgCl_2-醇的均匀溶液,再用TiCl_4与多元酸酯处理,得到含钛化合物等的MgCl_2载体催化剂.这种催化剂具有很高的活性和定向能力,生成的聚丙烯性能良好.但是按此方法需在较高温度(130℃)下进行醇合反应.本研究使用乙醇与乙酸酐的混合物和无水MgCl_2在卤代烷烃中进行反应,生成的均匀溶液经TiCl_4处理后得到了所谓AR-催化剂.这种MgCl_2载体催化剂具有良好的催化性能.
Complex of MgCl2.2CH3COOC2H5 with H2O was formed when anhydrous magnesium chloride reacted with the mixture of acetic anhydride and absolute ethyl alcohol in 1,2-dichloroethane. IR study showed that the water produced during the course of reaction could be coordinated to anhydrous magnesium chloride to form a complex H2O-MgCl2.2CH3COC)C2H5 with better stability. MgCl2-supported Ti catalyst was prepared by the interaction of- H2O-MgCl2. 2CH3COOC2H5 with TiCl4 and ester. This MgCl2-supported Ti catalyst exhibited very high activity and high stereospecificity for the polymerization of propylene and had good kinetic feature.
