Investigation of Thermodynamic Parameters for Steel Corrosion in Acidic Solution in the Presence of N,N′-Bis(phloroacetophenone)-1,2 propanediamine

Abstract

N,N′-Bis(phloroacetophenone)-1,2-propanediamine as corrosion inhibitor for steel in hydrochloric acid has been studied using electrochemical techniques and surface techniques. Results showed that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency was found to increase with increasing inhibitor concentration and decreased with increasing temperature. Thermodynamic parameters for adsorption and activation processes were determined. Polarization data indicated that this compound acts as the mixed-type inhibitor and the adsorption basically obeys the Langmuir adsorption isotherm. The quantum chemical calculations were performed at the density functional theory level using B3LYP functional with the 6-31G (d,p).