Mechanism of Antiozonant Action. I. Consumption of p-Phenylenediamines in Rubber Vulcanizates during Ozonization

Abstract

Abstract The consumption of N,N′-bis(1-methylheptyl)- and N-isopropyl-N′-phenyl- p - phenylenediamine in cis -polybutadiene vulcanizates was measured as a function of the ozonization time and the initial diamine concentration. The results are consistent with a rapid reaction of the antiozonants with ozone and the formation of a protective layer on the surface of the rubber. Film formation was confirmed by microscopic studies. Besides direct reaction with ozone and film formation, chemical reactions between the p -phenylenediamines and ozonized rubber took place since a certain amount of the consumed diamine (up to 45 %) became attached to the rubber network.