3,5-二溴水杨醛缩2,6-二异丙基苯胺钛化合物的合成及催化性能研究

STUDY ON PREPARATION OF NOVEL TITANIUM COMPLEXES BEARING TWO PHENOXY-IMINE CHELATE LIGANDS AND THEIR CATALYTIC PERFORMANCE

以价廉易得的水杨醛和2,6二异丙基苯胺为主要原料,通过溴代、缩合等反应合成了3,5二溴水杨醛缩2,6二异丙基苯胺配体,再与TiCl4配位形成了未见文献报道的新化合物[O(3,5-diBr)C6H2oCH=N2,6(iPr)2-C6H3]2TiCl2(A)。通过MS、1HNMR和元素分析表征了配体分子结构,通过1HNMR和元素分析表征了配合物(A)分子结构。以甲苯为溶剂,MAO(甲基铝氧烷)为助催化剂,钛配合物(A)在60℃,0.2MPa下,催化乙烯聚合活性为8.90×106gPE/(molTi·h·MPa),远高于水杨醛亚胺钛配合物[OC6H4oCH=N2,6(iPr)2C6H3]2TiCl2(B)催化乙烯聚合的活性,且所得聚乙烯分子量较高。考察工艺条件对催化性能的影响,结果表明:在常温～60℃范围内升高反应压力和温度,催化活性和产物分子量均能有效提高。

Salicylaldimine ligand and its titanium complexes, bis[N (3,5 dibromosalicylidene) 2,6 anilinato] titanium (IV) dichloride (A) are synthesized . Ligand is characterized by mass spectra, 1H NMR and elemental analyses and complex (A) is characterized by 1H NMR and elemental analyses. In the presence of MAO, the complex (A) in toluene are able to catalyze ethylene polymerization efficiently. Under conditions of T = 60℃, P =0.2 M Pa and n (MAO) / n (cat)=150 0, activity for catalyst A reaches 8.90×106 g PE /(molTi· h·bar) is much higher than that bis [N salicylidene 2,6 diisopropylanilinato] titanium(Ⅳ) dichloride(B). The effects of reaction conditions on polymerization are examined in detail. Increase in ethylene pressure and rise in polymerization temperature are favorable to raise catalytic activity and molecule weight.