Fatty acid oxadiazoles as acid corrosion inhibitors for mild steel

Abstract

2‐undecane‐5‐mercapto‐1‐oxa‐3, 4‐diazole (UMOD), 2‐heptadecene‐5‐mercapto‐1‐oxa‐3, 4‐diazole (HMOD) and 2‐decene‐5‐mercapto‐1‐oxa‐3, 4‐diazole (DMOD) were synthesized in the laboratory and their influence on the inhibition of corrosion of mild steel in 1N HCI and 1N H₂SO₄ was investigated by weight‐loss and potentiodynamic polarization techniques. The inhibition efficiency of these compounds was found to vary with concentration, temperature and immersion time. Good inhibition efficiency (IE) was evidenced in both acid solutions, remaining high (> 90 per cent) even at the concentration of 25ppm. The adsorption of these compounds on the steel surface for both acids was found to obey Temkin’s adsorption isotherm. The values of activation energy and free energy of adsorption indicated physical adsorption on mild steel surface. The potentiodynamic polarization data have shown that compounds studied are mixed type inhibitors.

Citation

Ajmal, M., Jamal, D. and Quraishi, M.A. (2000), "Fatty acid oxadiazoles as acid corrosion inhibitors for mild steel", Anti-Corrosion Methods and Materials, Vol. 47 No. 2, pp. 77-82. https://doi.org/10.1108/00035590010316412