Cedar tar as a green corrosion inhibitor for E24 steel in 1 M HCl solution: A comparative analysis of uncleaned and cleaned cedar tar

Abstract

Cedar tar was obtained from a local producer located in Timhdite, Morocco, and it was subsequently cleaned using distilled water.The chemical composition analysis of both the uncleaned (UNC-CDT) and cleaned (C-CDT) cedar tar was performed using gas chromatography (GC-MS).To investigate its inhibitory effect on E24 steel corrosion in a 1 M HCl solution, electrochemical impedance spectroscopy and Tafel polarization curves were employed.The study also examined the influence of concentration and temperature on the inhibition's effectiveness, and the surface morphology was analyzed through SEM-EDX.The chemical composition analysis revealed that both UNC-CDT and C-CDT were characterized by three main compounds with the highest percentages: epi--Caryophyllene at 15.78% and 13.27%, followed by -himachalene at 7.89% and 8.13%, and finally, (E)-Atlantone present at 6.06% and 5.21%, respectively.The electrochemical measurements showed that the inhibitory effect of Cedar Tar increased with concentration, reaching 93.09% and 95.51% at 1.5 g/L for UNC-CDT and C-CDT, respectively, at 293 K.The study observed that the organic components of cedar tar bind to metal surfaces through chemical and physical adsorption.The inhibitor exhibited good adsorption on the surface of E24 steel, following the Langmuir adsorption isotherm.As the inhibitor concentration increased, a thicker layer of inhibitor effectively covered the surface.In a 1 M hydrochloric acid solution, cedar tar proved to be an efficient corrosion inhibitor for E24 steel.Further studies are required to deepen our understanding and assess the full potential of wood tar as a corrosion inhibitor.