EIS study of epoxy paints in two different corrosive environments with a new filler: rice husk ash

In this paper, the corrosion behavior of the filled epoxy paint with the rice husk ash RHA on steel substrates in two different corrosive environments natural sea water and 2M sulfuric acid has been studied. Electrochemical impedance spectroscopy EIS was used to evaluate protective properties of different organic coating systems due to the different filler composition. RHA was prepared by heating rice husk at 700 º C for 3 hours. By adding RHA, as a new and natural filler, to the epoxy paint, the resistance to penetration of the solution was increased in both environments. The best filler for the sea water was the white RHA contained more silica in 20 wt. due to increasing the corrosion resistance for 3 times with respect to the unfilled epoxy paint. The black RHA contained more carbon- group increased the corrosion resistance of the epoxy paint in sulfuric acid when added in 20 wt.