O]CpTiCl) containing bisphenoxy ligands is discribed
while their composition and structure are characterized by elemental analysis
IR and 1H-NMR
suggesting that the ring structure is formed by the combination of the two oxygen atoms in the biphenol ligand [O
O] and the titanium atom.It is proved by the experiments that [O
O] CpTiCl is active for ethylene polymerization at 30℃ and latm with MAO activation
and exibits much higher activity that CpTiCl3
and the results show that the activity decreases successively with increase in the aromatic ings(C6H4O2)>(C12H8O2)>(C20H12O2).For the(C6H4O2)CpTiCl/MAO system
the activity is a“up and down” type with increase in the Al/Ti molar ratio
and up to the highest value around 1×105 gPE/molTi·h when the Al/Ti molar ratio is 500 to 3000.The polyethylene obtained is characteristic of bi-model distribution with an average molecular weight Mw=12.5×104 and molecular weight distribution Mw/Mn=7.4