الفهرس | Only 14 pages are availabe for public view |
Abstract The present work is aimed to Synthesis compounds with low toxicity and good inhibition efficiency against carbon steel corrosion. In this respect, two new Schiff bases (S1, S2) and their metal complexes (C1, C2, C3 and C4) were synthesized and their chemical structures were confirmed using FT-IR, 1HNMR and elemental analysis. The prepared compounds were evaluated as corrosion inhibitors for carbon steel in acidic medium, 1 M HCl, using two different types: gravimetrical and electrochemical methods. The gravimetrical (weight loss) measurements were studied at different temperatures (25, 40, 55 and 70 oC) and different concentrations (100-500 ppm). The thermodynamic and kinetic parameters of adsorption were calculated including the standard free energy (ΔGoads), entropy (ΔSoads) and enthalpy (ΔHoads) and the activation energy (Ea), Enthalpy and entropy of activation (ΔH*, ΔS*). The adsorption of all additives obeys the Langmuir adsorption isotherm, physical adsorption type and inhibitors acts as mixed type behaviors. The results obtained from the polarization technique are in good agreement with those obtained from weight loss method and OCP data. Corrosion inhibition efficiencies are in the order of (C2 > C1 > C4 > C3 > S1 > S2). |