Inhibition of lead corrosion with saturated linear aliphatic chain monocarboxylates of sodium

The ability of sodium monocarboxylates to inhibit the aqueous corrosion of lead was investigated. Electrochemical measurements (R-p, i(cor)) have show n that the inhibiting efficiency of these compounds, with a general formula CH3(CH2)(n-2)COONa (n = 7-11), is dependent on the carbon chain length and the concentration. The greatest inhibiting efficiency was observed for the longest carbon chains, sodium decanoate or undecanoate at a concentration of 0.01 M. Lead carboxylates were synthesised and their solubilities were determined. The potential-pH diagram of lead in water containing undecanoate anions was drawn taking into account the presence of lead carboxylate, Metal passivat ion was attributed to the growth of passive layers containing metallic soap , which was confirmed by XRD analysis and SEM observations of the treated l ead surfaces, (C) 2001 Elsevier Science Ltd. All rights reserved.