Synthesis, Characterization and evaluation of two organic compounds as corrosion inhibitors for carbon steel alloy (C1010) in acidic medium of 0.1M HCl.

Abstract

    In this study, 4-chlorobenzodithioatebenzyltrimethylammonium and 4-methoxylbenzodithioatebenzyltrimethylammonium were synthesized and characterized by ¹H-NMR, FTIR, UV-Visible and Mass techniques. Then they evaluated as corrosion inhibitors for carbon steel alloy (C1010) against corrosive environment of hydrochloric acid at different concentrations at 25 ˚C. both inhibitors revealed an excellent inhibition efficiency (97.95) % and (97.13) % at optimal concentrations (9) ppm and (8) ppm respectively. The effect of temperature on the corrosion was studied in absence and presence of the inhibitor, the raising of temperature leads to reduce the efficiency of the inhibitor and CR was enhanced. On the other hand, kinetic parameters such as activation energy , enthalpy of activation , entropy of activation and Gibbs free energy of activation  were calculated which are insisted a physical adsorbed behavior for the inhibitor, an endothermic corrosion reaction whether in presence or in absence of the inhibitor and enhanced non-spontaneous behavior in presence of the certain inhibitor. Each one of the inhibitor has the mixed inhibition behavior.