Ethoxylated fatty amines as corrosion inhibitors for carbon steel in hydrochloric acid solutions

Abstract

The effect of three compounds of non ionic surfactants, namely, ethoxylated fatty amines with different number of ethylene oxide unit on the corrosion of carbon steel (Type L52) in 1 M HCl has been studied using weight loss and galvanostatic polarization measurements. The percentage inhibition efficiency was found to increase with increasing concentration of inhibitor, number of ethylene oxide units and with decreasing temperature. The inhibitive effect of these compounds was interpreted in view of their adsorption on the steel surface, through their ethoxy groups. The adsorption of these compounds was found to obey the Langmuir isotherm. The effect of temperature on the rate of corrosion in the absence and presence of these compounds was also studied. Some activated thermodynamic parameters were calculated.