Ti-Hf双金属高效载体催化剂合成宽分子量分布聚乙烯的研究  

MgCl_2-supported Titanium and Hafnium Bimetallic High Activity Catalyst for Ethylene Homo-and Copolymerization

作　　者：李三喜[1] 

机构地区：[1]沈阳化工学院材料科学与工程系,沈阳110021

出　　处：《应用化学》2001年第5期412-415,共4页Chinese Journal of Applied Chemistry

基　　金：辽宁省科学技术基金项目! (0 0 2 0 0 8);辽宁省教育厅高等学校科学研究项目! (2 0 0 12 0 6 6 )

摘　　要：采用化学反应法 ,以氯化镁、醇化合物以及 Ti和 Hf化合物等为原料 ,制备了新型 Ti-Hf双金属载体催化剂 .乙烯聚合结果表明所得载体催化剂具有良好的催化活性 ,所得聚合产物呈现良好的颗粒形态 .与在相同条件下制备的只含 Ti的催化剂相比较 ,Ti-Hf双金属载体催化剂具有更良好的综合性能且生成分子量更高、分子量分布更宽的聚乙烯 ,在乙烯 -丁烯共聚中可生成密度更低的乙烯共聚物 .产物的熔流比随 H2气分压的增加而降低 .结合 GPC观察的结果 ,表明 Ti活性中心生成低到中等分子量的聚乙烯 ,而 Hf活性中心生成高分子量的聚乙烯 .Titanium and hafnium bimetallic catalyst prepared by chemical reaction method using MgCl 2 as support shows a high activity and good polymer particle size distribution. Compared with catalyst containing only titanium, the titanium-hafnium bimetallic catalyst exhibits better performance and produces polyethylenes with higher molecular weight and wider molecular weight distribution and gives lower density copolymer of ethylene with butene-1. The MFR values of polyethylene obtained decrease with increase in partial hydrogen pressure. High molecular weight shoulders in GPC profile demonstrates that moderate or low molecular weight polyethylene is due to the titanium species while the hafnium active species produce high molecular weight polyethylene. This bimetallic catalyst is suggested to have a promising application in production of polyethylenes with broad molecular weight distributions.

关 键 词：乙烯 聚合 丁烯 共聚合 双金属催化剂 催化合成 聚乙烯 钛 铪 活性中心 

分 类 号：O632.12[理学—高分子化学] O643.361[理学—化学]