Long-chain branched polyethylene was obtained using a homogeneous bianary catalyst system composed of late and early transition metal complexes

namely a mixture of bis(α-naphthalidine)-2

3-butanediimine) NiBr2 and Cp* TiCl3

as catalyst precursors in the presence of MAO．The binary catalyst system shows a good synergic effect

the polymerization activity is as high as 6×105g PE/mol(Ni+Ti)·h at i>XNi=0.8 and higher than that of either single Ni or Ti catalyst．The structure of PE was confirmed by 13C-NMR not only containing methyl

ethyl

butyl

amyl side groups

but also significant amount of long chain branches(n≥6)．The explanation for this is that ethylene oligomerized in the Ni catalyst active site and the oligomers containing vinyl end group served as comonomers to in situ copolymerize with the growing polyethylene chain in the active site of titanium catalyst．GPC curve of the resulting polyethylene obtained with this binary catalyst system showed a bimodal molecular weight distribution.