聚丙烯催化剂聚合性能的研究

Study on performance of polypropylene catalyst

采用磷酸酯类作内给电子体,MgCl_2作载体合成球形聚丙烯催化剂,以三乙基铝为助催化剂,甲基环已基二甲氧基硅烷为外给电子体,研究液相本体法聚合条件对催化剂性能的影响,并对聚合物进行了分析。结果表明:该催化体系最佳聚合条件为搅拌转速150 r/min,反应温度75℃,n(A1)/n(Ti)为600,n(Si)/n(Ti)为30。在此条件下,催化体系为长效型,催化剂活性高、氢调敏感性好,聚合物等规指数高、细粉少。

The author synthesized spherical catalyst for polypropylene （PP） using an organic phosphate as internal electron donor and MgCl2 as carrier. The effects of the liquid phase bulk polymerization conditions on the properties of the catalyst were studied in the case of using triethyl aluminum as cocatalyst and cyclohexylmethyldimethoxy-silane as external electron donor. The resultant polymer was analyzed. The results show that the optimum polymerization conditions suitable for the catalytic system are as follows： stirring rate 150 r/min, reaction temperature 75 ℃, molar ratio of Al/Ti 600 and Si/Ti 30. The catalytic system under such conditions shows the characters of long service life, high activity and good sensitivity to hydrogen modulation; the polymer produced with the catalyst has high isotacticity and less fine powders.