Study on synthesized corrosion inhibitor of chitosan and menthone based on Schiff base for carbon steel in the acidic environment

s Background Exploring effective and eco-friendly corrosion inhibitors is critical for Metal protection against an aggressive environment. This work investigated the performance of a newly synthesized menthone (5-methyl-2-(1-methyl-ethyl) cyclohexanone) and chitosan Schiff base for Q235 carbon steel in 1.0 M HCl. Methods The newly synthesized structure of MCS is confirmed using the FT-IR and 1H NMR spectrum. The inhibitor performance was evaluated using the weight loss. technique across a 298 – 328 K temperature range, electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP). SEM, AFM images, and X-ray photoelectron spectroscopy is employed to analyze the Q235 carbon steel Surface. Additionally, the adsorption behavior of MCS was studied using the Langmuir model isotherm and computational studies, including DFT, Fukui functions, and molecular dynamics simulations. Significant findings The results demonstrated the effectiveness of the MCS inhibitor. Achieving the highest inhibition efficiency of 95.9 % at an optimized concentration of 600 mg. L -1 . The electrochemical investigations suggest a mixed mechanism for the inhibitor. Surface analysis indicates that the adsorption of MCS molecules on the metal surface reduces corrosion. The adsorption mechanism of the inhibitor on the surface of the Fe metal occurs through physio-chemisorption, as inferred from the Gibbs free energy (ΔG ads ) value of -34 kJ. mol -1. Molecular dynamics simulations confirmed the stable adsorption of the inhibitor on the Fe (110) surface, with an adsorption energy of –941.564 kcal/mol for the neutral form.