Rubber like (amourphous) polyethylene with crystallinity of about 1 to 14% was prepared using a late metal catalyst of bis (2,6-isopropyl phenyl) 1,4-diazobutadine Nickel(II) dibromide [(2,6-i-prph)2 DABMe2]NiBr2. The optimum activity of the catalyst was observed at [Al]:[Ni] = 3333:1 molar ratio and of polymerization temperature of 25° C of polymerization. Higher concentration of MAO than the optimum value not only decreased the activity of the catalyst but also produced polyethylene-wax (PE-Wax). The rate/time profile of the polymerization was a decay type with an acceleration period of about 60 min at polymerization temperature of 25° C. The polyethylene produced at temperature lower than 50° C showed rubberly (amourphous) behavior while the reaction at 65° C produced PE-Wax. Activity of the catalyst was increased with monomer pressure to 5 atmosphere which studied. The viscosity average molecular weight ( V M ) of the polymer obtained was 7.5 ×104 at the monomer pressure of 3 bars and 35° C temperature.

Keywords