(二苯甲酰甲烷基)(环戊二烯基)二氯化钛/MgCl2-SiO2/MAO中各组分对乙烯聚合的影响

研究开发了一种新型非茂负载乙烯聚合催化剂 CpTi(dbm)Cl2 MgCl2 SiO2 MAO ,并考察了该催化剂中各组分对乙烯聚合活性的影响 .结果表明 ,SiO2 不仅可以改善催化剂的流动性和分散性 ,还有益于提高催化活性 .MgCl2 对活性中心有一定化学改性作用 ;MgCl2 、SiO2 和CpTi(dbm)Cl2 的比例的变化对载体型催化剂的催化活性有一定影响作用 ;采用适量的MAO对复合载体MgCl2 SiO2 活化 ,能提高催化活性 .用ZnCl2 MAO对SiO2处理制成的复合载体催化剂CpTi(dbm)Cl2 MgCl2 ZnCl2 SiO2 MAO ,可以提高催化活性 ,“锌调”作用明显 ,随着锌化合物含量的增加 ,聚合物相对分子质量下降 ,相对分子质量分布加宽 ,并且其催化活性也增加 .

THE EFFECT OF CONSTITUENTS OF CpTi(dbm)Cl2/MgCl2-SiO2/MAO ON ETHYLENE POLYMERIZATION

MgCl 2-SiO 2 supported monocyclopentadienyl titanium complex containing β-diketone ligand catalyst,CpTi(dbm)Cl 2/MgCl 2-SiO 2/MAO,was prepared and the effect of the content of this supported catalyst on catalytic activity was investigated.The activity is greatly influenced by the content of Ti,Mg and SiO 2.The activity of the catalyst can be improved by adding SiO 2 with good flowability and treating MgCl 2-SiO 2 with MAO,and the influence of Mg on the activity of Ti is also important for improving the catalytic activity.Another supported catalyst,CpTi-(dbm)Cl 2/MgCl 2-ZnCl 2-SiO 2/MAO,whereas SiO 2 was treated by MAO and ZnCl 2 previously,was prepared and its catalysis for ethylene polymerization was investigated.The activity increases with increasing the ZnCl 2 in feed,while the molecular weight of polymers decreases and the molecular weight distribution broadens.