Mild steel corrosion inhibition in 200 ppm NaCl by new surfactant derivatives of bis-glucobenzimidazolones

Abstract

The new bis-glucobenzimidazolone derivatives (24a–d) have been synthesized and characterized by NMR spectroscopy. They have been tested as corrosion inhibitor for mild steel in 200 ppm NaCl solution using potentiodynamic polarization curves and electrochemical impedance spectroscopy. Potentiodynamic polarization curve measurements showed that the investigated compounds were a mixed-type inhibitor. Their inhibition efficiencies improve with concentration and reached a maximum at 10−5 M of each compound and the 24b is better. Electrochemical impedance spectroscopy measurements showed that the diagrams composed of two depressed capacitive loops. This loop can be split into two capacities’ contributions, although badly separated. The first loop is attributed to the formation of a protective layer and the second is attributed to the charge transfer resistance.

Keywords

• Bis-glucobenzimidazolone derivatives
• Syntheses and characterization
• Corrosion inhibition
• 200 ppm NaCl
• Mild steel
• Electrochemical measurements