Novel cationic surfactant based on triazole as a corrosion inhibitor for carbon steel in phosphoric acid produced by dihydrate wet process

The corrosion inhibition effect of novel cationic surfactant based on tolyltriazole on carbon steel in 7 M H3PO4 solution has been evaluated by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods. The inhibition efficiency increases with increasing inhibitor concentration, but it decreases with increasing the temperature. The adsorption of inhibitor is mixed physical and chemical adsorption and found to obey the Langmuir adsorption isotherm. Data obtained from EIS studies were analyzed to model inhibition process through appropriate equivalent circuit model. Potentiodynamic polarization studies have shown that the inhibitor acts as a mixed type of inhibitor. Scanning Electron Microscopy (SEM) study also confirmed the protection of the metal surface by the used cationic surfactant. (C) 2015 Elsevier B.V. All rights reserved.