Corrosion inhibition of 1018 carbon steel with some ethoxylated fatty amides in hydrochloric acid solution

F.M. Al-Nowaiser

Chemistry Department Faculty of Science., King Abdulaziz University., P.O. BOX 80203 Jeddah, 2159 (Saudi Arabia).

Received on March 22, 2010 and accepted on April 28, 2010

ABSTRACT

The effect of three compounds of ethoxylated fatty amides with different number of ethylene oxide unit on the corrosion of 1018 carbon steel in 1M 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 unit and with decreasing temperature. The inhibitive effect of these compounds was explained on the basis of adsorption on the metal surface, through their ethoxy groups. The adsorption process follows Langmuir adsorption 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.

Keywords : 1018carbon steel,ethoxylated fatty amide, inhibitors