The role of new phosphonate derivatives on the corrosion inhibition of mild steel in 1M H2SO4 media

The inhibition performances of sodium methyldodecylphosphonate (pho1) and sodium methyl (11-methacryloyloxyundecyl) phosphonate (pho2) on mild steel corrosion insulfuric acid solution were studied using the electrochemical impedance spectroscopy (eis) and tafel polarization techniques. the experimental results suggest that those compounds are effective corrosion inhibitors and the inhibition efficiency increases with the increase ininhibitors concentrations. polarization measurements proved that the inhibitors behave as mixed-type. eis diagram appears a large capacitive loop at high frequencies (hf) followed by a small inductive loop at low frequencies (lf) for pho2,and the addition of this inhibitor increases the impedance of electrode. the adsorption of each inhibitor on steel surface obeys langmuir adsorption isotherm. the thermodynamic and kinetic parameters were calculated and discussed. values of inhibition efficiency calculated from weight loss,tafel polarization curves,and eis are in good agreement.