Applications of infra‐red spectroscopy to surface coatings

Abstract

A survey is made of the apylications of infra-red spectroscopy in the surface coatings field, especially in connexion with (1) the chemistry of drying oils, particularly with reference t o the geometrical isornerization of f a t t y acids, the autoxidation process and copolymerization of oils with unsaturated compounds; (2) the curing of epoxy resins, and (3) the identification of synthetic resins.The permeation of polychlorotrifluoroethylene by nitric acid has been found t o occur at a limited number of sites in the surface of the film. 1 hese sites have been detected using paper impregnated with a suitable indicator and also by microscopical examination ; they were found to be randomly distributed and were mainly macro-or visible cracks. Counts have been made of the numbers and size distribution of the cracks. Infra-red spectrometry was used t o investigate whether chemical reactions occurred between nitric acid and the fluorinated plastic film, but no evidence of chemical degradation products was found.