Inhibitive and Adsorption behaviour of date Palm Hemicellulose on Mild Steel Corrosion in Sulfuric Acid Media

摘要

The effectiveness of Date Palm Hemicellulose (DPH) as corrosion inhibitor of mild steel in sulfuric acid medium (pH=2) at 20-40 C°, was studied using Potentiodynamic polarization and electrochemical impedance methods. The corrosion rate and the inhibition efficiencies of (DPH) were calculated. (DPH) acted as an efficient mixed type inhibitor. The adsorption of (DPH) on the mild steel surface obeyed Redlich-Peterson adsorption isotherm (g = 0.98) and (R~2 = 99.99%). The calculated adsorption thermodynamic parameters indicated that the adsorption was a spontaneous (AG°ad = - 3.2 KJ/mol.), exothermic (ΔH°_(ad)= -14.97 KJ/mol.) process accompanied by a small increase in entropy (56.48 J/K mol.)