宽或双峰分子量分布HDPE的研制——Ⅰ.双金属复合催化剂的制备及其催化乙烯聚合反应动力学

Study on Wide or Bimodal Molecular Weight Distribution HDPEⅠ . Preparation of Bimetallic Composite Catalyst and its Reaction Kinetics in Ethylene Catalytic Polymerization

将Cp_2ZrCl_2以一定方式负载于BCH催化剂上制备出了双金属复合催化剂,研究了BCH/Cp_2ZrCl_2对载锆量的影响以及负载温度对双金属复合催化剂催化性能的影响,并用X射线光电子能谱法证实了茂金属催化剂确已载到了BCH催化剂上。催化乙烯聚合的动力学研究表明,双金属复合催化剂的动力学曲线与BCH催化剂一样均属衰减型;由于双金属中心的存在,其动力学曲线出现了2个峰值。

Bimetallic composite catalysts were prepared by supporting Cp2ZrCl2 on BCH catalyst. The influence of the ratio of the BCH to Cp2ZrCl2 on Zr loading amount and the effect of temperature of making catalyst on the catalytic properties were studied. The analysis of X - ray photoelectron spectroscopy (XPS) confirmed that the metallocene was indeed supported on the BCH catalyst. The kinetic study of ethylene polymerization showed that the polymerization curve of the bimetallic composite catalyst belonged to the attenuation mode, similar to that of the BCH catalyst. Two peaks occurred in the kinetic curve of the bimetallic composite catalyst because of the presence of its double metallic active centers.