析出型聚乙烯催化剂颗粒成形条件的研究  

Study on conditions for forming of precipitated polyethylene catalyst particles

作　　者：吕新平[1] 王世波[1] 周俊领[1] 周歆[1] 黄廷杰[1] 张长礼[1] 

机构地区：[1]中国石化北京化工研究院,北京100013

出　　处：《石油化工》2017年第2期196-201,共6页Petrochemical Technology

摘　　要：以MgCl_2和钛酸四丁酯为原料,采用析出法制备了溶解析出型Ziegler-Natta催化剂,利用粒径分布和溶体流动指数测定等方法,通过乙烯聚合考察了催化剂制备条件对催化剂和聚合物性能的影响。实验结果表明,镁钛配合物质量浓度为100~500 g/L时制备的催化剂的活性基本为(1.6~1.8)×10~4 g/g;镁钛配合物质量浓度为100~400 g/L时制备的催化剂平均粒径为14~16μm。适宜的催化剂颗粒成形温度为15~45℃,在该温度范围内,聚合物堆密度为0.35 g/cm^3左右。随颗粒成形温度的升高,催化剂粒径分布变宽。随卤化剂用量的增大,催化剂平均粒径呈先增大后减小的趋势。搅拌转速550 r/min下制备的催化剂聚合所得聚合物粒径分布最优。随卤化剂滴加速度的加快,制备的催化剂聚合所得聚合物粒径分布变宽。A Ziegler-Natta catalyst was prepared from MgCl2 and tetrabutyl titanate by the dissolving- precipitating method. The effects of catalyst preparation conditions on the properties of both the catalyst and the produced polymer were investigated. It was showed that the activity of the catalyst was （1.6-1.8）× 10^4 g/g when the magnesium-titanium complex mass concentration was in the range of 100-500 g/L. The average particle size of the catalyst was in 14-16 μm when the magnesium-titanium complex mass concentration was in the range of 100-400 g/L. Under the appropriate catalyst particle forming temperature of 15-45 ℃, the bulk density of the produced polymer was 0.35 g/cm3. The particle size distribution of the catalyst became wider with the catalyst particle forming temperature rise. The particle size distribution of the prepared polymer was the best when the stirring speed in the catalyst preparation process was 550 r/min. The particle size distribution of the produced polymer with the catalyst became wider with increasing the dropping speed of halogenating agent.

关 键 词：溶解析出 ZIEGLER-NATTA催化剂 乙烯聚合 聚乙烯 

分 类 号：TQ426.62[化学工程]