The study of the inhibitory properties of Omeprazole on the corrosion of Aluminum 6063 in alkaline media

Abstract

The influence of (6-Methoxy-2-(4-methoxy-3,5-dimethyl-pyridin-2-yl-methanesulfinyl) or Omeprazole(OME) on the corrosion of aluminum 6063 in 2M NaOH solution has been studied using hydrogen evolution (gasometry) measurement at 30 and 55 °C temperature. The results suggest that OME acts as a good inhibitor and the inhibition efficiency increases with increasing the concentration of OME. The %I decrease with increase in temperature from 30 to 55°C in the absence and the presence of inhibitor and halides. The adsorption of inhibitor followed Temkin adsorption isotherm and the value of ∆Gads, Ea,, and Qads values suggests that it is physical adsorption. The synergism parameters (S1) obtained were found to be greater than unity between I- ,Br-, Cl- ions and OME, which indicates that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism. Some quantum chemical parameters and the Mulliken charge densities for OME were calculated by the semi-empirical AM1method to provide further insight into the mechanism of inhibition of the corrosion process.