以乙醇为溶剂,2-羟基1-萘醛与2,6-二异丙基苯胺通过希夫碱缩合得到一种新型萘氧基亚胺配体1a。配体1a在四氢呋喃(THF)溶剂中分别与NaH和TiCl4.2THF反应得到相应的钛配合物1。气相色谱-质谱联用(GC/MS)表征了配体结构,核磁共振氢谱(1H NMR)、元素分析等手段表征了配合物1。甲苯为溶剂,MAO(甲基铝氧烷)为助催化剂,0.6 MPa乙烯压力下30—70℃时钛配合物1催化乙烯聚合活性为2.66×105—7.24×105g PE(mol Ti)-1h-1,所得聚乙烯粘均分子量较高(3.5×104—25.5×104),将反应压力从0.1 MPa提高到1.0 MPa,1/MAO催化体系活性和聚合产物分子量能大幅提高。配合物1的活性具有明显的温度效应,在60℃达到最高。GPC和DSC表征结果说明所得聚合物为窄分布低支化度聚乙烯。

Synthesis of Novel Titanium Complex Bearing Two Naphthyloxy-imine Chelate Ligands and Its Catalytical Performance for Ethylene PolymerizationCHENG Zheng-zai,WU Lin,LV Zao-sheng,YAN Xiao-chao,TANG Ping(Department of Chemistry Engineering,Wuhan University of Science and Technology,Wuhan 430081,China)Reaction of 2-hydroxyl-1-naphthaldehyde with 2,6-di-isopropyle-aniline via Schiff base condensation in ethanol afforded the corresponding naphthyloxy-imine ligand 1a.Ligand 1a was characterized by mass spectra.Treatment of this ligand with NaH and TiCl4·2THF in THF respectively,a new titanium complex 1 was obtained of which the structure was characterized by 1H NMR and elemental analyses.Activated by MAO,Complex 1 displayed a very high activity for ethylene polymerization.Under the conditions of T=30—70 ℃ and P=0.6 MPa,the activities achieve 2.66×105—7.24×105 g PE(mol Ti)-1h-1 and the viscometric average molecular weight(Mv) of polyethylene was from 35 000 to 255 000.The activities and the Mv increase with the pressure from 0.1 MPa to 1.0 MPa.The temperature effect on activity of complex 1 is very strong.The data characterized by GPC and DSC showed the synthesis of linear polyethylene(LPE).naphthyloxy-imine;titanium complex;catalyst;ethylene polymerization