聚合条件对聚丙烯球形HA催化剂聚合活性的影响

Influences of Polymerization Conditions on Activity of Spherical HA Catalysts for Propylene Polymerization

采用聚丙烯球形HA催化剂进行丙烯聚合,利用本体聚合法和常压淤浆聚合法考察了聚合条件对聚合活性的影响.实验结果表明,HA催化剂具有较高的聚合活性,且当三乙基铝与催化剂中钛的摩尔比（简称Al/Ti比）较低时仍可保持较高的聚合活性.在常压淤浆聚合中,随Al/Ti比的增大,HA-Ⅰ催化剂的聚合活性衰减速率加快.在丙烯本体聚合中,适当降低Al/Ti比对HA-Ⅱ催化剂的聚合活性影响不大,且可降低聚合活性的衰减速率.外给电子体的加入会降低HA催化剂的聚合活性.随加氢量的增大,HA催化剂的聚合活性先增加后略有降低.HA-Ⅰ催化剂催化丙烯本体聚合时,聚合温度选择70～ 75℃较适宜.

Propylene polymerization was conducted with spherical HA catalysts.The influences of polymerization conditions on the activity of the catalysts were investigated by bulk and slurry polymerizations.The results indicated that the HA catalysts had high activity,even though in low mole ratio of triethyl aluminum to Ti （Al/Ti）.In the slurry polymerization,the activity attenuation speed of the HA-Ⅰ catalyst increased with the increase of Al/Ti.In the bulk polymerization,with decreasing Al/Ti,the activity of the HA-Ⅱ catalyst kept uninfluenced and its activity attenuation speed reduced.External donors would reduce the activities of the HA catalysts.The activities of the HA catalysts first increased and then decreased with increasing H2 amount.When the HA-Ⅰ catalyst was used in the bulk polymerization of propylene,the optimum polymerization temperature was in the temperature range of 70-75 ℃.