带有大位阻基团的α-二亚胺镍配合物催化乙烯聚合  

Ethylene polymerization catalyzed by nickel(Ⅱ) α-diimine complexes with large steric hindrance group

作　　者：侯彦辉[1,2] 路小敏 王涛[3] 姜湃 杨敏[4] 胡博文[4] 翟飞帆 刘宾元[4] 

机构地区：[1]天津工业大学材料科学与工程学院,天津300387 [2]天津工业大学省部共建分离膜与膜过程国家重点实验室,天津300387 [3]河北科技大学资产设备处,石家庄050018 [4]河北工业大学化工学院,天津300130

出　　处：《天津工业大学学报》2016年第6期38-44,共7页Journal of Tiangong University

基　　金：河北省自然科学基金资助项目(B2015202049);中国石油科技创新基金资助项目(2015D-5006-0502)

摘　　要：为提高α-二亚胺镍催压剂的耐热性,选用对位带有不同电子效应取代基的2,6-二(二苯甲基)苯胺,并与苊醌反应制备α-二亚胺配体.研究发现:带有吸电子基团的三氟甲基使此反应难以进行,只能得到单亚胺产物;而带有供电子基团的甲氧基可以活化该反应,对应的α-二亚胺配体产率达到82%.采用2,6-二(二苯甲基)-4-甲氧基苯胺制得α-二亚胺镍配合物,在一氯二乙基铝的作用下催化乙烯聚合,考察聚合条件对催化活性及聚合物结构、性能的影响.研究结果表明:在70℃、0.5 MPa聚合压力下催化剂的活性为1.58×106g/(mol·h),所得聚乙烯的支化度为64/1 000 C;随着聚合温度的升高,聚乙烯分子质量降低,支化度升高,熔点降低;聚合压力的提高使催化剂活性增加,聚乙烯的熔点升高,支化度降低.To improve the heat resistance of α-diimine-nickel catalyst, a series of 2,6 -bis （diphenylmethyl）anilines, withdifferent substituent on the parα-position of the benzene ring, were synthesized and used to prepare α-diimine ligands by reacting with acenaphthenequinone. It was found that the electron-drawing trifluoromethyl made the reaction become very difficult, and only imine was got. However, the electron-donating methoxyl on aniline could initiate the reaction and the corresponding α-diimine ligand was obtained in high yield of 82%. So, the α- diimine-nickel complex based on 2,6-bis（diphenylmethyl）-4-methoxylaniline was chosen as catalyst, with di- ethylaluminium chloride, to polymerize ethylene. The effects of experimental conditions on catalytic activity of the nickel complex and the structures and properties of polyethylene were investigated. Under pressure of 0.5 MPa, the catalyst showed the highest activity at 70 ℃ （1.58×10^6g/（mol·h））. The branching degree of the ob-tained polyethylene is 64/1 000 C. As the reaction temperature increased, the molecular weights of the obtained polyethylene decreased, but the branching degree rised, which lead to the decrease of melting points. The in-creasing of polymerization pressure made the activity of catalyst and the melting point of polyethylene increase and the branching degree decrease.

关 键 词：大位阻基团 α-二亚胺镍催化剂 乙烯聚合 支化聚乙烯 电子效应 

分 类 号：TQ316.3[化学工程—高聚物工业]