Investigation of corrosion inhibitory effect of hydroxyl propyl alginate on mild steel in acidic media

摘要

The anti-corrosion effect of hydroxyl propyl alginate (HPA) on mild steel in 1M HCl has been studied by chemical (weight loss) and electrochemical (polarization and electrochemical impedance spectroscopy) methods. From all the three methods, it is inferred that there is an increase in inhibition efficiency with increase in concentration of the inhibitor. Polarization studies revealed the mixed mode of inhibition by HPA. The mode of adsorption is physical in nature. The adsorption of HPA on mild steel followed Frumkin adsorption isotherm. The thermodynamic and kinetic parameters have been calculated and discussed. Surface morphological studies have been carried out with Scanning electron microscopy (SEM) and Atomic force microscopy (AFM). Fourier transform infrared spectroscopy (FTIR) is utilized to characterize the adsorbed film. SEM and AFM methods confirm the presence of inhibitor on the surface of the metal. (C) 2015 Wiley Periodicals, Inc.