Synthesis of New Pyridine Based 1,3,4-Oxadiazole Derivatives and their Corrosion Inhibition Performance on Mild Steel in 0.5 M Hydrochloric Acid

The influence of three newly synthesized oxadiazole derivatives on the corrosion inhibition of mild steel in 0.5 M HCl solution was studied using mass loss and electrochemical techniques. The corrosion rate decreased with increasing concentration of inhibitors and increased with increase in temperature of the medium. Adsorption of the all the three inhibitors obeyed the Langmuir isotherm model. Polarization curves indicated that the inhibitors are of mixed type. Electrochemical impedance spectroscopy measurements explained the mechanism of action of inhibitors. Various activation and adsorption thermodynamic parameters were calculated. The surface adsorbed film was characterized by scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX). The electronic properties of the inhibitors were obtained from AM1 semiempirical quantum chemical approach. Excellent correlation was found between theoretical and experimental results.