Effects of alcohol-based inhibitors on corrosion of mild steel in hydrochloric acid

The inhibition efficiencies of Octyl alcohol (OCAL) and propargyl alcohol (PRAL) on the corrosion of mild steel in 15% commercial hydrochloric acid have been evaluated by mass loss method, electrochemical techniques and surface analysis techniques with 0-1% inhibitor concentration at 30 degrees C and 105 degrees C. Both OCAL and PRAL are excellent inhibitors for the above-mentioned system. OCAL gives 87% and 82% inhibition efficiencies at 30 degrees C and 105 degrees C, respectively, for 1% inhibitor concentration whereas PRAL gives 100% and 99% efficiencies at 30 degrees C and 105 degrees C, respectively, for 0.6% inhibitor concentration. Polarization studies confirm that OCAL and PRAL are mixed type inhibitors. OCAL and PRAL obey Temkin's adsorption isotherm at both the temperatures. UV-reflectance, FT-IR and SEM studies confirm that the surface of mild steel is not affected at the maximum concentration of OCAL and PRAL (C) 2009 Elsevier B.V. All rights reserved.