Modazar as promising corrosion inhibitor of carbon steel in hydrochloric acid solution

Abstract

Modazar drug was tested as corrosion inhibitor for carbon steel in 1 M HCl solution using chemical (weight loss and gasometric) and electrochemical (open {circdeg;}uit potential, potentiodynamic polarization, electrochemical frequency modulation and electrochemical impedance spectroscopy) techniques. The results showed that the inhibitory efficiency increased with the increase in drug concentration reaching a maximum value of 92.3% at 300 ppm while it decreases with increasing the temperature. Polarization curves showed that Modazar drug is a mixed type inhibitor but the cathode is more polarized than the anode. The drug was adsorbed physically on the C-steel surface obeying Langmuir adsorption isotherm. The morphology of the surface of the specimens was analyzed using atomic force microscopy, energy dispersion spectroscopy and scanning electron microscopy. The results obtained from chemical and electrochemical techniques are in good agreement.

Keywords

• Modazar drug
• acid corrosion
• EIS
• EFM
• EDX