THE INFLUENCE OF N-HEXADECYL BENZYL DIMETHYL AMMONIUM-CHLORIDE ON THE CORROSION OF MILD-STEEL IN ACIDS

The influence of N-hexadecyl benzyl dimethyl ammonium chloride or cetyl benzyl dimethyl ammonium chloride (CBDMAC) on the corrosion of mild steel in 5 N and 5.5 N solutions of H2SO4 and HCl has been studied using techniques such as weight loss and gasometric measurements, potentiodynamic polarisation studies, linear polarisation studies and small amplitude cyclic voltammetric studies. Inhibition efficiencies have been obtained both from weight loss and gasometric measurements. The effectiveness of the inhibitor at higher acid strength is also examined using 8 N acid solutions. Polarisation studies reveal that the inhibitor behaves as an anodic inhibitor in H2SO4 and as a mixed inhibitor in HCl solutions. Measurements of values of polarisation resistance (R(p)) and the double layer capacity (C-dl) have been carried out. The effect of temperature on corrosion inhibition has been studied and activation energies for both the acids have been evaluated, The inhibition of corrosion of mild steel in both the acids has been attributed to micelle formation. The adsorption of the inhibitor on the mild steel surface from both the acids is found to obey the Temkin adsorption isotherm.