CORROSION INHIBITION BEHAVIOR OF N,N′-BIS(2,4,6- TRIHYDROXYACETOPHENONE)-PROPANDIIMINE ON ST44.0 STEEL IN ALKALINE NACL SOLUTION

The inhibition behavior of N,N?-bis(2,4,6-trihydroxyacetophenone)-propandiimine (THAPP) as an environmentally friendly Salen Ligand on the corrosion inhibition of mild steel was studied in alkaline solution (pH=10) containing 3% NaCl. Measurements were carried out using electrochemical and surface techniques. The experimental results suggested that this compound was an effective corrosion inhibitor for mild steel and the protection efficiency was increased with the increase in inhibitor concentration. Polarization curves indicated that this organic compound was a mixed-type inhibitor. Adsorption on the mild steel surface follows the Langmuir isotherm model. Activation parameters and thermodynamic adsorption parameters of the corrosion process such as Ea, ?H, ?S, Kads, and ?Gads were calculated by the obtained corrosion currents at different temperatures.