不同形貌介孔材料催化剂的制备及在乙烯聚合中的应用

利用面包圈状、棒状、高比表面积球状和空心球状4种不同形貌的介孔材料作为载体负载甲基铝氧烷和茂金属双（正丁基环戊二烯基）二氯化锆（BuCp）制备负载型茂金属催化剂,并在2 L不锈钢高压聚合釜进行高压乙烯聚合小试试验。文中研究了4种反应器的组成、结构和微观形貌。扫描电镜、小角X光粉晶衍射、氮气吸附-脱附测试结果表明,4种不同形貌介孔材料在负载茂金属后仍然保持较好微观形貌及其特有的介孔材料孔道结构,负载茂金属后反应器的孔结构参数较负载前有所减小,孔壁厚度有所增强,表明茂金属成功进入介孔材料孔道中。元素分析结果表明,所得催化剂表面的Al元素质量分数范围为16%～22%,Zr元素质量分数范围为0.4%～0.7%。聚合试验结果表明,催化剂对乙烯均聚和共聚的活性均优于当前工业用载体955硅胶负载同样茂金属后的乙烯均聚和乙烯和己烯共聚的活性,其中空心球状介孔材料反应器为最适合乙烯聚合的催化剂。

Supported metallocene onto multi-morphological mesoporous materials for polymerization of ethylene

Four kinds of catalysts have been prepared by supported(n-BuCp)2ZrCl2 and MAO onto the mesoporous materials with different morphologies including rod-like,sphere-like,doughnut-like and hollow sphere-like shapes firstly and successfully.The structure and morphology of the catalysts have been studied.And the catalysts have been investigated for the polymerization of ethylene.The result of ethylene homopolymerization and ethylene/1-hexene copolymerization catalyzed by metallocene adduct catalyst confirmed that catalyst possessed higher activity in copolymerization and homopolymerization than 955 silica gel,and that hollow sphere-like catalyst is the most suitable carrier for ethylene polymerization.