α-二亚胺镍催化剂催化乙烯溶液聚合的性能

Solution polymerization of ethylene by α-diimine nickel catalyst

合成了4种不同结构的配体及6种α-二亚胺镍金属配合物,并表征了配体及配合物的结构。结果表明:所合成的配合物显示出较高的活性和优异的热稳定性;以甲基铝氧烷为助催化剂,甲苯为溶剂,聚合温度为100℃时,配合物Ni3的活性可达3.45×10~6 g/(mol·h);配体结构对催化剂活性和所得聚合物的结构具有较大的影响;用配合物Ni1制备的聚合物的重均分子量为1.8×10~4;采用具有较大位阻的配合物Ni3可得到更高相对分子质量的聚合物。

Four different ligands and sixα-diimine nickel complexes were synthesized and characterized.These complexes have shown high catalytic activities and excellent thermal stability.The complex Ni3shows the highest activity of3.45×106g/(mol·h)at100℃with methylaluminoxane as cocatalyst and toluene as solvent.The structure of the catalyst contributes to the catalytic activity and polymer structure significantly.The weight average molecular weight of the polymer prepared by complex Ni1is1.8×104,and the polymer in higher molecular weight can be obtained by complex Ni3containing more steric hindrance.