Effect of some ethoxylated fatty acids on the corrosion behaviour of mild steel in sulphuric acid solution

The inhibition of the corrosion of mild steel in 1.0 M sulphuric acid solution by some ethoxylated fatty acids OL[E)](20), OL[EO](40) and OL[EO](80) has been studied in relation to the concentration of the inhibitors as well as the temperature using chemical (weight loss) and electrochemical (potentiodynamic polarization) techniques. The inhibition efficiency increases with increasing the concentration and the chain length of the inhibitor but decreases with temperature. The inhibition was assumed to occur via adsorption of the fatty acid molecules on the metal surface. The thermodynamic functions of dissolution and adsorption processes were calculated. (C) 1999 Elsevier Science S.A. All rights reserved.