The Mode of Attack of Oxygen on Rubber
SourceIt has long been recognized that rubber, because of its unsaturation, is degraded by atmospheric oxygen, and, in contrast with most unsaturated materials, a very small degree of oxidation is sufficient to destroy its characteristic properties.
The oxidation of rubber, whether vulcanized or unvulcanized, is a complicated process, involving several reactions, each of which is influenced differently by conditions. The existence of more than one reaction is illustrated by reference to the influence of: (1) a given material on raw and vulcanized rubber, (2) chemicals on mill breakdown, (3) different antioxidants in an otherwise similar stock, (4) combinations of metal catalysts, (5) oxygen pressure on the temperature coefficient of the oxidation, (6) temperature on the amount of oxygen required for degradation, and (7) different aging conditions.