Theobroma cacao seed oil as corrosion inhibitor for steel saline and acidic environment

Abstract

Corrosion is a significant cause of structural failure because it deteriorates steel and damages its physical and mechanical characteristics. Saline water and acid exposure of steel metals contribute to faster corrosion activity affecting the integrity of steel on various structural components, and the application of corrosion inhibitors may extend steel's serviceability. This study investigated the corrosion inhibition properties of Theobroma cacao seed oil on steel. The weight-loss method was used to determine the corrosion rate and inhibition efficiency in steel submerged in saline and acid solutions as corrosion baths with varying concentrations of Theobroma seed oil extract. The results indicate that in 1M of H2SO4, the maximum efficiency rate of the medium was 70.75%, with an inhibitor concentration of 0.8 mg/L. On the other hand, 98.72% inhibition efficiency was demonstrated in artificial saline water at an inhibitor concentration of 0.2 mg/L. These results demonstrate that the presence of T. cacao seed oil on steel slows corrosion at all concentrations through the absorption of amino acids that form a protective layer.