【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.更多还原

【Abstract】 To improve the heat resistance of α-diimine-nickel catalyst, a series of 2,6-bis(diphenylmethyl)anilines, with different substituent on the para-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 diethylaluminium 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 0.5MPa, the catalyst showed the highest activity at 70 ℃(1.58×106g/(mol·h)). The branching degree of the obtained 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 increasing of polymerization pressure made the activity of catalyst and the melting point of polyethylene increase and the branching degree decrease.更多还原