Effect of trimethylaluminum on the polymerization of ethylene with the catalytic system Bis[N-(3,5-di-tert-butylsalicylidene)-2,3,5,6-tetrafluoroanilinato]titanium(IV) dichloride-methylaluminoxane

The effect of trimethylaluminum in commercial methylaluminoxane on the molecular-mass characteristics of polyethylene formed with the phenoxyimine titanium catalyst bisN-(3,5-di-tert-butylsalicylidene)-2,3,5,6-tetrafluoroanilinato]titanium(IV) dichloride activated by methylaluminoxane of varying purity is studied. It is shown that, all other conditions being equal, an increase in the content of trimethylaluminum in the reaction solution leads to an appreciable decrease in the molecular mass of the polymer. With an increase in the time of polymerization, the molecular mass tends to increase, while overall polydispersity indexes M _w/M _n remain substantially less than 2. The causes of the above effects are discussed.