球形高效丙烯聚合催化剂的合成及性能

Synthesis and Property of Spherical High Activity Catalyst for Propylene Polymerization

关键词:  MgCl2/SiO2  复合载体  Ziegler-Natta催化剂  聚丙烯

Key words:  silica/magnesium chloride  Ziegler-Natta polymerization  high impact polypropylene

摘要:

通过喷雾干燥法制备了MgCl2/SiO2复合载体,并分别采用AlEt3为助催化剂、邻苯二甲酸二正丁酯(DNBP)为内给电子体,以甲基环己基二甲氧基硅烷(CHMDMS)为外给电子体制备了丙烯聚合催化剂。通过液相本体聚合的方法研究了该催化体系催化丙烯液相本体聚合的性能。结果 表明该类催化剂具有活性高、立体定向性好、颗粒形态好、氢调敏感性好等优点,所得的聚丙烯产物复制了催化剂的形态,呈规则的球形。该催化剂可用于丙烯的液相本体+气相组合工艺制备高抗冲聚丙烯,所得丙烯抗冲共聚物的低温性能得到了显著提高。

Abstract:

The MgCl2/SiO2 complex support was prepared by spray drying using alcoholic suspension which contained MgCl2 and SiO2.The complex support reacted with TiCl4 and di-n-butyl phthalate,giving catalyst for propylene polymerization. TEA and CHMDMS were used as a cocatalyst external donor, respectively. The bulk polymerization of propylene was studied with the catalyst system. The results showed that the catalyst had high activity, high stereospecificity and sensitive hydrogen responsibility. Polypro-pylene has good grain morphology because of duplicating the morphology of the catalyst. The catalyst can be used in combination technology of liquid phase bulk and gas phase for high impact PP.