Reinforcement of Natural Latex Rubber by Carbon Black and Ionizing Radiation

The study of the reinforcement of rubber by carbon black has made it possible to establish the radical nature of the interaction, thus explaining why, in the latex phase and in the absence of sources of radicals, the reinforcing effect of carbon black does not exist and why it has been possible up to the present to obtain it only by mastication of the solid rubber in the presence of black. Irradiation, an excellent source of radicals, should in latex systems lead to a reinforcement of rubber by black. The experiments carried out appear to prove this. Irradiation of the latex and the black in aqueous dispersion, followed by a mixture of the two constituents which is then poured out on a plate, dried and subjected to moderate thermal treatment, makes it possible to obtain mechanical properties which are definitely superior to those of films prepared without irradiation and of films vulcanized with sulfur.