Inhibition of Corrosion of Mild Steel in Hydrochloric Acid Solution Using Akee Apple Seed Extract

The inhibiting action of Akee apple (Blighia sapida) seed extract (AASE) on corrosion of mild steel was investigated in 2 M hydrochloric acid solution using weight loss and thermometric measurements. The study was carried out at temperatures of 30 and 60 °C with concentration of inhibitor varied from 0.1 to 0.5 g/l in the acidic medium. The results of the study showed that the corrosion rate of mild steel decreased in the presence of the inhibitor but increased with increase in temperature. The inhibitor exhibited excellent inhibition efficiency on mild steel corrosion as 86.90 and 75.87% of inhibition efficiency were achieved with addition of 0.5 g/l concentration of the inhibitor at 30 and 60 °C temperature, respectively. The inhibitive adsorption parameters established that the AKEE obeyed the Langmuir adsorption isotherm with physical adsorption mechanism and the result of Gibbs free energy of adsorption (∆Gads) revealed an endothermic reaction and spontaneous process of adsorption. © 2018, ASM International.