新型聚丙烯催化剂的聚合性能

Performance of novel catalyst for propylene polymerization

研究了以新型含镁化合物为载体的HQ型聚丙烯高效球形催化剂的液相本体聚合,考察了聚合温度,n(Al)/n(Ti),n(Si)/n(Ti),外给电子体种类,氢气用量对催化剂催化性能的影响。结果表明:该催化剂具有良好的氢调敏感性和立体定向性。最适宜的聚合条件:反应温度为70℃,n(Al)/n(Ti)为481.0,外给电子体为甲基环己基二甲氧基硅烷,n(Si)/n(Ti)为19.2。在此条件下,HQ型催化剂的活性达34.0 kg/g,聚丙烯等规指数为97.9%以上。

The authors studied liquid phase bulk polymerization of propylene in the presence of a high efficiency spherical HQ catalyst with novel magnesium compounds as carrier. The effects of the polymerization temperature, molar ratio of Al to Ti and Si to Ti, type of external electron donor and Hi amount on the catalyst＇s performance were explored. The results show that the catalyst has excellent sensibility to hydrogen response and high stereospecifieity. The optimal polymerization conditions included polymerization temperature of 70℃, molar ratio of Al to Ti of 481.0, molar ratio of Si to Ti of 19.2 and taking methyl eyclohexyl dimethoxysilane as external electron donor. Under such conditions, the catalyst＇s activity reaches 34.0 kg/g and the isotaetieity of the polypropylene product exceeds 97.9%.