Inhibition Behaviour of 2-[(2-Methylquinolin-8-yl) Oxy] Acetohydrazide on the Corrosion of Mild Steel in Hydrochloric Acid Solution

A hydrazide derivative containing quinoline moiety namely 2-[(2-methylquinolin-8-yl)oxy]acetohydrazide (MQH) has been synthesized and its corrosion inhibition performance and adsorption behaviour on mild steel in 0.5 and 1 M HCl solution have been tested by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The inhibition efficiency of MQH increases with increase in its concentration and decreases with increase in HCl concentration. Further the, inhibition efficiency of MQH increases in 0.5 M HCl and decreases in 1 M HCl with increase in temperature. Polarisation curves indicate that MQH is a mixed inhibitor, affecting both cathodic and anodic corrosion currents. The adsorption of MQH at the mild steel/HCl solution interface obeys Langmuir adsorption isotherm model and inhibition process follows mixed adsorption with predominantly chemisorption in 0.5 M and physisorption in 1 M HCl. The activation and thermodynamic parameters for the corrosion inhibition process have been calculated to explore the mechanism of corrosion inhibition.