N-aminophthalimide as a synthon for heterocyclic schiff bases: Efficient utilization as corrosion inhibitors of mild steel in 0.5 mol.L^-1 H₂SO₄ solution

MANY Schiff bases were prepared to inhibit the corrosion reactions of mild steel in acidic medium. Their chemical structures were determined by using different techniques. Thermodynamic adsorption parameters of inhibitors were determined using the Langmuir adsorption isotherm. The presence of iodide ions in the medium increased the efficiency of these inhibitors. AC impedance spectroscopy was used to determine the polarization resistance. The scanning electron microscopy (SEM) showed the corrosion products decreased after using these inhibitors. The results show that the planer inhibitor is more effective than rich-electron one because it covers the whole surface. In addition, the mechanism of these inhibitors depends on decreasing the anodic and cathodic current.