希夫碱钛配合物/三异丁基铝催化MMA本体聚合

Methyl Methacrylate Bulk Polymerization by Schiff Base-Titanium Complexes/Al(i-Bu)_3

经希夫碱缩合反应,制得水杨醛亚胺配体(1),其Na盐分别与TiCl4和CpTi-Cl3反应合成了新型希夫碱钛配合物{3,5-di-Br-2-(O)C6H2CHN[2(O)C6H4]}TiCl2(2);{3,5-di-Br-2-(O)C6H2CHN[2(O)C6H4]}[TiCl(C5H5)](3).以GC-MS,1HNMR和元素分析对中间产物及配合物进行了表征.以Al(i-Bu)3为助催化剂,详细考察了聚合时间、温度、Al/Cat和MMA/Cat的摩尔比对催化MMA本体聚合的影响.两个催化体系的聚合转化率均可以达到62%左右.2/Al(i-Bu)3(A)催化体系在聚合条件MMA/Cat(摩尔比)=2 000,Al/Cat(摩尔比)=20,T=60℃,t=15 h下,Mη可以达到3.6×105,相对分子质量分布2.14;3/Al(i-Bu)3(B)催化体系在相同聚合条件下,Mη可以达到4.3×105,相对分子质量分布2.44.红外光谱分析表明,A,B两个催化体系所得的PMMA的间同含量分别为85%和86%左右.

Substituted salieyladimine ligand （1） was prepared by sehiff base condensation, and its sodium salts reaeted with TiCl4 and CpTiCl3, giving the novel Titanium complexes 13,5-di-Br-2-（O） C6H2CHN [ 2 （O） C6H4] }TiCl2（2） ; {3,5-di-Br-2-（O）C6H2CHN[2（O）C6H4] J [TiCl （C5H5） ] （3） bearing Sehiff base ligands. All complexes were characterized by ^1HNMR and element analysis. In combination with Al（i-Bu）3, both 2/Al（i-Bu） 3 （A） and 3/Al（i-Bu） 3 （B） were aetive to initiate methyl methaerylate （MMA） polymerization. The influence of reaetion parameters sueh as Al/Cat molar ratio, MMA/Cat molar ratio, time and temperature on polymerization have been examined in detail. The polymerization conversion of A and B reached 62 %. Under the polymerization condition （MMA/Cat（molar ratio） = 2 000, Al/Cat（molar ratio） = 20, T = 60 ℃, t = 15 h） of A system, Mη and MWD of PMMA reached 3.6 × 10^5 and 2.14 respectively. Under the same polymerization condition, B system, Mη and MWD of PMMA reached 4.3 × 10^5 and 2.44, respectively. From IR analysis, the syndiotaetie content of PMMA obtained by A and B were about 85 % and 86 % respectively.