ANALYSIS OF PIGMENTED POLYMER-COATINGS WITH RADIOFREQUENCY GLOW-DISCHARGE OPTICAL-EMISSION SPECTROMETRY

With a radiofrequency (r.f.) source, glow discharge optical emission s pectrometry is capable of depth-profiling materials such as the pigmen ted polymers used on pre-painted steel. A method is now available for converting the recorded, qualitative r.f. depth-profiles into quantita tive depth-profiles of concentration versus depth. The paper reports t he results from the first test programme of the new method. The method is tested here with a range of laboratory prepared polymers with know n pigment loadings. Samples include various concentrations of the prin ciple white pigment, rutile, in the polymer, followed by a set with a range of mixed red and white pigments. The ability of the method to de termine the pigment loadings and to distinguish the different pigments is assessed.