MgCl_2醇合改性对Ziegler-Natta催化剂活性的影响  

Effect of MgCl_2 Alcohol-Adduct Modification on Activity of Ziegler-Natta Catalyst

作　　者：杨俊凤[1] 范玲婷[1] 李贺[1] 吴志祥[1] 许胜[1] 米普科[1] 

机构地区：[1]华东理工大学材料科学与工程学院,上海200237

出　　处：《石油化工》2011年第8期840-844,共5页Petrochemical Technology

摘　　要：以无水MgCl2为载体,负载TiCl4制备了Ziegler-Natta催化剂——TiCl4/MgCl2;采用正交实验探讨了醇合改性处理中各因素对催化剂活性的影响,确定了影响催化剂活性的主次因素;进一步考察了n(醇)∶n(Mg)、醇合改性剂种类及醇合时间等因素对催化剂催化乙烯淤浆聚合活性的影响。以正己烷为溶剂、异丁醇为醇合改性剂,当n(醇)∶n(Mg)=3.5、醇合时间2.5h、醇合温度70℃时制备的催化剂的聚合活性较高。在n(Al)∶n(Ti)=200、聚合温度45℃的常压淤浆聚合条件下,催化剂的聚合活性为2 094g/g(基于每克催化剂的聚乙烯质量),聚乙烯的重均相对分子质量为4.3×105,相对分子质量分布为10.0,结晶度为68.34%,支化度为1.028%。The Ziegler-Natta catalyst system was prepared by the traditional way with anhydrous MgCl2 as the support. The effects of n （ROH） ： n （Mg）, solvent type, alcohol type and alcohol-adduct time on the catalyst preparation and the ethylene polymerization were investigated by the orthogonal method. Under the optimal conditions： n-hexane as the solvent, isobutyl alcohol as the alcohol-adduct modifying agent, n（alcohol） ： n（Mg） 3.5, alcohol-adduct time 2.5 h and alcohol-adduct temperature 70℃ for the catalyst preparation, and 45℃ and n （Al） ： n （Ti） 200 for the ethylene slurry polymerization, the activity of the catalyst system in the polymerization was 2 094 g/g （ polyethylene mass based on 1 g catalyst）. Additionally, Mw, Mw/Mn, crystallinity and branching degree of the obtained polymer were 4.3×10^5 , 10.0, 68.34% and 1. 028%, respectively.

关 键 词：氯化镁 醇合 四氯化钛 负载型Ziegler—Natta催化剂 乙烯淤浆聚合 聚乙烯 

分 类 号：TQ426.92[化学工程]