乳液成型乙烯聚合催化剂的性能

摘要

采用乳液成形法制备了一种新型聚乙烯催化剂(BCN).利用元素分析、粒度分析和SEM等方法对BCN催化剂的组分、粒径及形态进行了表征.表征结果显示,BCN催化剂的粒径较小,粒径分布较窄且颗粒均匀.考察了BCN催化剂的聚合性能.实验结果表明,BCN催化剂聚合活性较高;氢调敏感性优异,当P(H2)∶p(C2H4)在0.28∶0.72～ 0.70∶0.30之间时,聚乙烯的熔体流动指数(10 min)在2.8 ～ 390.0 g之间可调;随共聚单体1-己烯加入量的增大,BCN催化剂的聚合活性呈先增大后减小的趋势,制得的聚乙烯的支化度则逐渐增大,而堆密度逐步减小.采用BCN催化剂有利于生产装置的长周期平稳运行.%A new polyethylene(PE) catalyst(BCN) was prepared by an emulsification method.The composition,particle size and morphology of BCN catalyst were characterized by means of ICP,particle size analysis and SEM.The results showed that the particle size of BCN catalyst was small and its distribution was narrow.The performance of BCN catalyst was studied and the results indicated that BCN catalyst had high activity and excellent sensitivity to hydrogen.When p(H2) ∶ p(C2H4) was between 0.28 ∶ 0.72 and 0.70 ∶ 0.30,the melt index(10 min) of the product PE is adjustable between 2.8 g and 390.0 g.With increasing co-monomer 1-hexene dosage,the activity of BCN catalyst first increased and then decreased; the branching degree of the product PE gradually increased; and its bulk density reduced.Using BCN catalyst will be beneficial to steady running of PE plants in a long period.