Abstrato

Dimethyl Pyrimidine Derivatives as Corrosion Inhibitors for Carbon Steel in Hydrochloric Acid Solutions

A. S. Fouda, Y.M. Abdallah and D. Nabil

The effect of some prepared compounds, namely 4,6-dimethyl pyrimidine derivatives (P-Cl), (P-NMe2) and (P-OH) on the corrosion of C-steel in 1 M HCl solutions has been studied using the weight loss, potentiodynamic polarization, electrochemical frequency modulation (EFM) and electrochemical impedance spectroscopy (EIS) techniques. The results showed that the inhibition efficiency of the investigated compounds was found to depend on the concentration and the nature of the inhibitor. The efficiency of the inhibitors increases with the increase in the inhibitor concentration but decreases with a rise in temperature. Polarization results indicated that these compounds behave as mixed type inhibitors. The adsorption of these compounds on steel surface followed Langmuir adsorption isotherm. The reactivity of investigated compounds was analysed through quantum chemical by PM3 method to explain the efficiency of these inhibitors as corrosion inhibitors. The scanning electron microscope (SEM) results showed the formation of a protective film on the metal surface in the presence of these additives.