Effect of the unsaturation of the hydrocarbon chain of fatty-amides on the CO2 corrosion of carbon steel using EIS and real-time corrosion measurement

Fatty-amide derivatives were evaluated to study the effect of the double bonds into the hydrocarbon chain (c18) on the corrosion behavior of carbon steel. electrochemical impedance spectroscopy (eis) and real-time corrosion measurements were used to evaluate the inhibition mechanism of the fatty-amides on carbon steel in co2-saturated (3% nacl + 10% diesel) emulsion at 50°c. eis results demonstrated that the unsaturation present into the hydrocarbon chain contributes to the efficiency of fatty-amides,because they can be adsorbed on the metal surface by a flat-adsorption process reducing the presence of active sites and blocking the corrosion process and preventing the diffusion of corrosive species,such as h2o,h+,cl-,and hc o 3 -. real-time corrosion measurements also indicated that the effectiveness of the inhibitors is dependent on the unsaturation into the hydrocarbon chain,being also a good technique to determine the stability of the adsorption process of the inhibitors. © 2015 j. porcayo-calderon et al.