The Antioxidants of Rubber Latex. I.

Abstract

Abstract Various authors have observed that raw rubber from which the acetone-soluble portions have been removed deteriorates much more easily than does crude raw rubber itself. It is certain that this deterioration is associated with an autoöxidation of the rubber. In this laboratory it has been proved in different ways that sheets of crude rubber may lie in the air for years without any change. On the contrary, rubber which has been purified according to Pummerer's method is extraordinarily sensitive to oxygen. If such a purified rubber lies in the air for a couple of days it loses its elasticity, becomes tacky and short, and finally becomes completely fluid. Accordingly there must be a substance in natural rubber which prevents the autoöxidation of the hydrocarbon, or at least retards it greatly. The object of the present work was to identify this substance, to isolate it, and to explain its constitution and its mode of action if possible.