Inhibition of Acid Corrosion of Pure Aluminum with 5-Benzylidine-1-Methyl-2-Methylthio-Imidazole-4-One

Inhibition of aluminum corrosion in 0.5 M hydrochloric acid (HCl) solution by 5-benzylidine-1-methyl-2-methylthio-imidazole-4-one was tested using weight loss and polarization resistance measurements. Results of tests for weight loss, polarization resistance, and volume of hydrogen evolution (V_HE) indicated inhibitor efficiency (% P) increased with increasing inhibitor concentration, reaching a maximum inhibiting power of 82.5% at its highest values. The rate of aluminum corrosion increased with temperature in the absence and presence of the inhibitor The decrease in activation energy and increase in % P in the presence of the inhibitor with increasing temperature were indicative of the chemisorption of inhibitor molecules. The degree of surface coverage (θ) increased with increasing temperature and increased linearly with the logarithm of the inhibitor concentration, fitting a Temkin isotherm.