水杨醛亚胺钛络合物的负载及在催化乙烯聚合中的应用

以3,5-二枯基水杨醛与2,3,4,5,6-五氟苯胺为原料缩合反应合成了水杨醛亚胺配体(Ⅰ),利用四氯化钛和水杨醛亚胺配体(Ⅰ)反应制得了相应的水杨醛亚胺钛络合物(Ⅱ),用核磁共振氢谱(¹H NMR)和核磁共振碳谱(¹³C NMR)表征了配体及络合物的结构。以甲基铝氧烷(MAO)为助催化剂,在60℃、1.0 MPa压力下,水杨醛亚胺钛络合物(Ⅱ)在甲苯中催化乙烯聚合活性为4.6×10⁷ g PE/(mol Ti),所得聚合物黏均分子质量为7.6×10⁵g/mol。以氯化镁/铝化合物为载体,制得高活性负载型水杨醛亚胺钛络合物(Ⅱ)催化剂,在60℃、1.0 MPa压力下,催化乙烯淤浆聚合活性达到24390 g PE/(g Ti),聚乙烯的黏均分子质量提升至4.3×10⁶g/mol,为超高分子量聚乙烯。

Immobilization of Bis-(phenoxy-imine)Titanium Complex and Application in Ethylene Polymerization

Salicylaldehyde imine ligand(Ⅰ)was prepared via the condensation reaction of 3,5-dicumyl-salicylaldehyde and 2,3,4,5,6-pentafluoroaniline as the starting material.Titanium tetrachloride was treated with the ligand to give the corresponding bis-N-(3,5-Dicumyl-salicylidene)-2,3,4,5,6-Pentafluoroanilinato]Titanium(Ⅳ)dichloride complex(Ⅱ).Both ligand and complex were characterized by proton nuclear magnetic resonance spectroscopy(¹H NMR)and carbon nuclear magnetic resonance spectroscopy(¹³C NMR).Ⅰn the presence of methylaluminoxane(MAO)as a cocatalyst,the complex(Ⅱ)displayed ethylene polymerization activity of 4.6×10⁷g PE/(mol Ti)at 60℃and 1.0 MPa in toluene,resulting in polyethylene with a viscosity average molecular weight value of 7.6×10⁵g/mol.And complex(Ⅱ)was supported on the MgCl₂/AlEt_n(OEt)_3-n.The supported catalyst exhibited a high activity of 24390 g PE/(g Ti)at 60℃and 1.0 MPa ethylene pressure,resulting in ultra-high molecular weight polyethylene with a viscosity average molecular weight value of 4.3×10⁶g/mol.