The kinetic study of butadiene polymerization with a cobalt-containing catalyst in hexane

The kinetics of butadiene polymerization in hexane initiated by a catalyst prepared through the interaction of cobalt 2-ethylhexanoate with ethylaluminum sesquichloride and isoprene in the absence of water at Co : Al : isoprene = 1 : 20 : 20 ( mol/ mol) has been studied. The reaction orders with respect to the monomer and cobalt ethylhexanoate are estimated as 1.45 +/- 0.04 and 1.5 +/- 0.3, respectively. The concentration of active centers of the catalyst turns out to be 60 mol % of the cobalt concentration, as determined by the fractional inhibition of polymerization with cyclopentadiene. The rate constant of chain propagation, as calculated from the kinetic data, appears to be 1700 l/(mol min). The effective activation energy is 25.1 +/- 7.5 kJ/ mol.