INHIBITION OF ACIDIC CORROSION OF ALUMINUM BY TRIAZOLINE DERIVATIVES

Inhibition of the corrosion of aluminum (Al) in hydrochloric acid (HCl ) by some triazoline derivatives was studied in relation to the concen tration of the inhibitors using gasometry, the weight-loss method, and the potentiodynamic technique. All compounds investigated were found to be inhibitors of the mixed type. The inhibitory character of the ad ditives depended upon the +R (resonance) and +I (inductive) powers of alkyl or aryl groups of the triazoline derivatives. Inhibition was asc ribed to the adsorption of the inhibitor onto the metal oxide surface following the Flory-Huggins isotherm. The compounds were adsorbed on t he metal surface. Each molecule of the inhibitors occupied an average of 3.8 active sites on the metal surface. The Values of activation fre e energies varied between -30 kJ/mol and -45 kJ/mol.