MONOMER-ISOMERIZATION POLYMERIZATION .28. CATALYTIC ACTIVITY OF TRANSITION-METALS AND ALKYLALUMINUMS IN MONOMER-ISOMERIZATION POLYMERIZATION OF 2-BUTENE

Monomer-isomerization polymerization of cis-2-butene (c2B) with Ziegler-Natta catalysts was studied to find a highly active catalyst. Among the transition metals [TiCl3, TiCl4, VCl3, VOCl3, and V (acac)3] and alkylaluminums used, TiCl3-R3Al (R = C2H5 and i-C4H9) was found to show a high-activity for monomer-isomerization polymerization of c2B. The polymer yield was low with TiCl4-(C2H5)3Al catalyst. However, when NiCl2 was added to this catalyst, the polymer yield increased. With TiCl3-(C2H5)3Al catalyst, the effect of the Al/Ti molar ratio was observed and a maximum for the polymer yields was obtained at molar ratios of 2.0-3.0, but the isomerization increased as a function of Al/Ti molar ratio. The valence state of titanium on active sites for isomerization and polymerization is discussed.