CONICET | Buscador de Institutos y Recursos Humanos

Abstract. The present work depicts synergism anticorrosive behaviour between zinc hypophosphite and zinc phosphatein a commercial pigment mixture. Also, the performance of anticorrosive paints was evaluated. Synergismanticorrosive behaviour was evaluated by corrosion potential and linear polarization measurements in pigment suspensions.The protective layer obtained with this pigment mixture was investigated by scanning electron microscopy(SEM). Then, the anticorrosive properties of the pigment were assessed by incorporating it into alkyd and epoxypaints which were evaluated by salt spray test and electrochemical noise technique. The morphology and the natureof the protective layer grown under the paint film were also studied by SEM. Experimental results showed thatimproved anticorrosion protection is achieved in paints with reduced zinc phosphate contents as a consequence ofthe synergistic interaction between zinc hypophosphite and the other components of the pigment mixture. The electrochemicalnoise technique proved to be adequate to monitor corrosion in painted panels and is able to detectcorrosion under the paint film from very early stages. This paper identified the need to study synergism betweenanticorrosive pigments to try to reduce the phosphate content in anticorrosive paints.