Investigation of the inhibitor effect of polyacrylic acid on the corrosion of mild steel in ethylene glycol-water mixture

The inhibitor effect of polyacrylic acid on the corrosion of mild steel in ethylene glycol-water mixture was investigated depending on the pH value and inhibitor concentration of the mixture. The results obtained using electrochemical impedance spectroscopy (EIS), current-potential curves and scanning electron microscopy (SEM) techniques showed that the corrosion rate was decreased with increasing pH value and inhibitor concentration. As the polyacryclic acid concentration increased, the inhibition efficiency increased due to more inhibitor adsorption on the mild steel surface and the protective film formed on the surface was confirmed by the SEM image. The highest inhibition efficiency was obtained as 90,7 % in the medium containing 4800 ppm inhibitor at pH 9,5.