Corrosion inhibition of mild steel in sulphuric acid by n-octylamine and iodoacetic acid

The influence of iodoacetic acid (IAA) on the corrosion inhibition of mild steel in 0.5 M sulphuric acid (H2SO4) containing octylamine (OA) has been s tudied using weightloss, polarization and a.c. impedence techniques. Corros ion data obtained by different methods are consistent. IAA and OA individua lly retard the corrosion of mild steel in sulphuric acid. The addition of I AA enhances the inhibitor efficiency of OA considerably. Adsorption of inhi bitors follows quasi-substitution process at the interfaces. OA cations are adsorbed by coulombic interaction on the metal surface, which is preoccupi ed by IAA molecules as dipoles. Adsorption model is suggested to account th e synergistic action of IAA on the corrosion inhibition of mild steel in su lphuric acid solution by OA.