Homo- and copolymerization of butadiene, isoprene, and styrene with catalytic systems based on transition-metal compounds and aluminoxanes

The structure, phase composition, and temperature behavior of homo- and cop olymers of butadiene, isoprene, and styrene synthesized with the catalytic systems composed of transition-metal compounds and isobutylaluminoxane were studied by IR and C-13 NMR spectroscopy, DSC, and X-ray diffraction analys is. It was shown that a VCl4-TiCl4 catalytic system combined with isobutyla luminoxane yields PB containing 95% trans-1,4 units. The catalytic systems derived from cobalt compounds with the varying ligand environment when comb ined with isobutylaluminoxane make it possible to prepare syndiotactic crys talline 1,2-PB containing 80-93% 1,2 units and having a syndiotacticity of up to 75%. The above cobalt catalytic systems were employed to initiate cop olymerization of butadiene with isoprene and styrene.