【摘要】 采用芳基亚胺桥联双核茂钛络合物催化乙烯聚合反应 ,考察了茂环上不同取代基、聚合温度、聚合时间和助催化剂用量对络合物催化活性和所得聚合物分子量的影响 .结果表明 ,该类络合物催化乙烯聚合的活性很高 ,所得聚合物具有较高的分子量和较宽的分子量分布 .络合物催化活性最高可达 3 4 2 0× 10 5g/(mol·h) ,所得聚合物分子量最高可达 6 5 9345 g/mol,分子量分布最宽为Mw/Mn=5 88.茂环上的取代基增大 ,络合物的催化活性提高 ,而且催化活性随着助催化剂甲基铝氧烷(MAO)用量的增大而增大 .聚合时间为 1 0h和聚合温度为 6 0℃时 ,络合物的催化活性最高 .更多还原

【Abstract】 Activated with methylaluminoxane(MAO), the μ-arylimido binuclear titanium complexes showed high activity for ethylene polymerization. The obtained polyethylene had high molecular weight (M η>1×10 5 g/mol) and broad molecular weight distribution (MWD, M w/M n>3.70). The complex [(η 5-C 5H 4CH 2C 6H 5)Ti-(Cl)(μ-NC 6H 4CH 3-2)] 2 (4) showed the highest catalytic activity (3.420×10 5 g/(mol·h), M η= 504*!403 g/mol, M w/M n=3.74), and the obtained polymer catalyzed by complex [(η 5-C 5H 4CH 2CH 2OMe)Ti(Cl)(μ-NC 6H 4CH 3-2)] 2 (3) displayed the broadest MWD (M w/M n=5.88). The activity of the complexes was affected greatly by the substituted group on the cyclopentadienyl ligand, and it increased from 1.189×10 5 g/(mol·h) to 2.75×10 5 g/(mol·h) when the steric hindrance of ligand enlarged from H to cyclohexanyl. The activity improved from 0.591×10 5 g/(mol·h) to 5.640×10 5 g/(mol·h) when the molar ratio of Al/Ti increased from 1*!000 to 4*!000 . The optimum polymerization conditions are θ=60 ℃ and t=1.0 h.更多还原