The reaction of diphenylaminyl and nitroxyl radicals and their role in the mechanism of the antioxidant effect of mixtures of an aromatic amine with nitroxyl

Research paper by L. I. Mazaletskaya, G. V. Karpukhina

Indexed on: 01 Feb '83Published on: 01 Feb '83Published in: Russian Chemical Bulletin


Diphenylamine is formed during thermal decomposition of tetraphenylhydrazine (TPH) in chlorobenzene in an amount close to the starting concentration of TPH.The kinetics of accumulation of diphenylamine is described by a set of stages of the decomposition of tetraphenylhydrazine, recombination and disproportionation of the diphenylaminyl radicals formed.The rate constant of the reaction of diphenylaminyl radicals with 2,2,6,6-tetrameth-yl-1-oxyl-piperidine was estimated; it was shown that this reaction does not affect the anti-oxidant effect of a mixture of an aromatic amine and the nitroxyl radical.The synergistic effect of a mixture of inhibitors InH with alkyl radical acceptors (Q) could be due to the reaction In. + Q → Products, if the rate of this reaction is greater than the rate of chain propagation In. + RH → InH + R..