Calix[4]titanium in combination with Al(iBu)3 formed a homogeneous catalyst system.This homogeneous catalyst system was found to be an active catalyst system for the polymerization of ethylene.The effects of Al/Ti molar ratio
solvent
concentration of catalyst and polymerization temperature on the polymerization were studied in detail.Polyethylene having Mw of 9.4×105 is obtained under following conditions:[Ti]=5×10-4 mol/L
Al/Ti=20
T=35℃
t=1h
ethylene pressure=1.0MPa.The catalytic activity is 60.7kg PE/mol Ti·h. Other alkyl aluminums as cocatalysts were also investigated.For various alkyl aluminums the catalytic activity decreased in the following order: AlEt3>Al(iBu)3>AlEt2Cl>Al(iBu)2Cl.