Corrosion protection properties of 4-hydroxy-N'-[(1E, 2E)-3-phenylprop-2-en-1-ylidene] benzohydrazide on mild steel in hydrochloric acid medium

The corrosion behaviour of mild steel immersed in 0.5 M HCl in the absence and presence of 4-hydroxy-N'-[(1E, 2E)-3-phenylprop-2-en-1-ylidene] benzohydrazide (HPB) was evaluated using Tafel polarization and electrochemical impedance spectroscopy techniques. The effect of inhibitor concentration and temperature on the corrosion inhibition efficiency (% IE) of HPB was studied and discussed. It is observed that the inhibition efficiency increased with increase in inhibitor concentration and also with increase in temperature for a give inhibitor concentration. The polarization study revealed that HPB acts as a mixed type of inhibitor by inhibiting both anodic and cathodic reactions. The corrosion inhibition process follows Langmuir-adsorption isotherm and takes place predominantly through chemisorption.