Abstract
Thanks to the numerous investigations of Moureu and Dufraisse, a large number of substances are now known which retard the autoöxidation of oxidizable substances. These retarding substances were given the name of antioxygens by the authors. Dufraisse and his collaborators have studied, with special attention to rubber, a certain number of antioxygens which greatly retard autoöxidation and the changes which take place during aging. In a preceding work I showed, by a study of different portions of the acetone extract of rubber, that certain substances exercise an antioxygenic effect which is the greater the more highly colored they are. The question then arose whether, in addition to antioxygens which act chemically, there may not be colored substances capable of retarding the autoöxidation of rubber by physical means by absorbing active luminous radiation. I thus ignored completely spontaneous autoöxidation, which is quite a different phenomenon from the one I did investigate. In the work referred to above, some experiments on colored substances were described which showed, for example, that azobenzene and α-benzeneazo-β-naphthylamine had a very great antioxygenic action, whereas alizarin and carotene were almost inactive. The present work will show whether colored substances are capable, by purely physical means, of preventing the autoöxidation of rubber and of substances allied to rubber, such as balata and gutta-percha.
Evaluation of the effect of TiO2 treatments on the reflectance to solar and luminous radiation of coating mortars.