MONOMER-ISOMERIZATION POLYMERIZATION .32. THE ROLE OF NICKEL COMPOUNDS (NIX2) IN MONOMER-ISOMERIZATION POLYMERIZATION OF 2-BUTENE WITH TICL3-NIX2-(C2H5)3AL CATALYST

The effects of nickel(2+) compounds, NiX2 (X = chloride, acetylacetonate, and dimethyl glyoximate) on monomer-isomerization polymerization of cis-2-butene with TiCl3-(C2H5)3Al catalyst were studied. NiX2 affected both isomerization and polymerization processes. Thus, addition of NiCl2 increased the yields of polymer, poly(1-butene), and a maximum yield (72.3% for 24 h) was obtained at Ni/Ti and Al/Ti molar ratios of 1 and 3, respectively ([Ti] = 50 mmol/L). These polymers have high molecular weights [(40-85) x 10(4)] and contain a significant isotactic fraction. Analysis of the composition of unpolymerized butene isomers in the reaction mixture indicates that their equilibrium concentrations determine the rate of reactions. The NiCl2-(C2H5)3Al catalyst induced the isomerization of cis-2-butene at a rate comparable to the TiCl3-NiCl2-(C2H5)3Al catalyst but did not produce a polymer.