Long chain imidazole derivative as a novel corrosion inhibitor for Q235 steel in 15 % HCl medium under hydrodynamic condition: Experimental and theoretical examinations

The research in the paper focused in the development of ecologically favorable inhibitor via microwave method. The inhibitor namely N-(2-(2-pentadecyl-2,5-dihydro-1H-imidazole-1-yl)ethyl)palmitamide palmitate, a derivative of imidazole (IPP) was synthesized in one single step and screened its inhibitive property in strongly acidic medium (15 % HCl) for protection of Q235 steel at 1500 rpm rotational speed. The study used for exploring the inhibition effect of IPP includes weight loss, Potentiodynamic polarization, and electrochemical impedance spectroscopy. The estimated results confirmed the inhibition data of 97.41 % and 98.70 % at 308K with 200 mg/L/only IPP and IPP + KI/150 mg/L+0.5 mM respectively, and the influence of temperature has little effect over the inhibition property. The weight loss results show that the IPP belongs to a mixed-type corrosion inhibitor. The SEM, EDX, AFM, SKP, and contact angle analysis results showed that the IPP formed a film on the surface of Q235 steel through adsorption, which changed the hydrophilic and hydrophobic properties of the Q235 steel surface. Further XPS study confirmed the adsorption of IPP molecules over the Q235 steel surface.