KINETICS AND MECHANISM OF OXIDATION OF POLYBUTADIENE CATALYZED BY MOLECULAR-OXYGEN

The catalytic oxidation of oligomeric cis-polybutadiene by molecular oxygen in the presence of complex compounds of Cu(II), Ni(II), and V(IV) was studied. It was shown that in the presence of the copper complex, the oxidation process has a free-radical chain-like character, and the copper chelate participates in the degenerated branching stage; the Ni(II) chelate catalyzes the oxidation of polybutadiene by a molecular or a latent-radical mechanism; and the VO(DMSO)-5(ClO4)2 complex - by a molecular mechanism. The polymeric oxidation products obtained in the presence of each of the catalysts were studied by the IR-Fourier spectroscopic method. It was found that the product obtained in the presence of Cu(II) chelate is identical with the product of the initiated oxidation of polybutadiene, whereby a degradation of the polymeric chain is thus observed; the Ni(II) compound promotes the formation of polymer containing the -OOH groups only in the alpha-position to the C=C bond with not more than one hydroperoxy group per repeating unit; in the presence of VO(DMSO)5(ClO4)2 a set of oxygen-containing products is obtained and the number of C=C bonds decreases.