双组分α-二亚胺镍复式催化剂制备长支链聚乙烯

SYNTHESIS AND PROPERTIES OF LONG CHAIN BRANCHED POLYETHYLENE WITH BINARY CATALYST SYSTEM

报道以两种后过渡金属催化剂二-(2,6-二甲基苯基)-丁二亚胺氯化镍和二-(2-甲基苯基)-丁二亚胺氯化镍所组成的复式催化体系,催化单一乙烯聚合可制备得到长支链(n≥6)的聚乙烯。在合适的聚合条件下此复式催化剂具有很好的协同作用,其催化活性比任一单一催化剂的催化活性都高。本文详细研究了两种催化剂的摩尔比、聚合温度等聚合条件对催化活性及产物结构的影响。用13C-NMR、FT-IR、DSC对聚合物进行了表征。

Branched polyethylene were obtained by using homogeneous binary catalyst system composed of two different α-Diimine Nickel catalysts in the presence of MAO. At appropriate polymerization conditions the binary catalyst system shows a good synergic effect, the polymerization activity is higher than any single catalyst. ^(13)C-NMR spectra of resulting PE exhibits methyl, ethyl, butyl, amyl and significant amount of long chain branches (n≥6) in the backbone of polyethylene. The molar ratio of two catalysts and the polymerization temperature(T_p) influence catalytic activity, molecular weight, degree of branching and melting point of the resulting polyethylene greatly.