Systematic Analysis of the Effect of Benzene on the Corrosion Inhibition Performance of Imidazoline Derivatives: Experimental and Theoretical Research

Imidazoline derivatives are widely used to prevent corrosion due to their toxicity and mitigation potential. The present study deals with the synthesis of two imidazole Schiff derivatives (JSMP and JSPP) based on imidazole hexanoate (JSMZ). The corrosion mitigation potential and mechanism in 1.0 mol L-1 HCl solution were studied with a focus on the influence of increasing the number of phenyl groups. The inhibitive performance was investigated by weight loss and electrochemical experiments. The accuracy of the corrosion protection mechanism was verified through scanning electron microscopy (SEM) + energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), and the corrosion inhibition mechanism was further verified through theoretical simulations (density functional theory and molecular dynamics). JSMP and JSPP formed a defensive layer over the surface of Q235. As the concentration of the corrosion inhibitor and the number of phenyl rings increased, the corrosion protection ability also increased gradually. The obtained corrosion protection effectiveness was 94.95% at 2.0 mmol L-1. JSMP and JSPP belong to a mixed type and predominantly cathodic inhibitors, which spontaneously adsorb on metal surfaces and follow Langmuir isotherm adsorption.

Oryza sativa plant extract in 15% hydrochloric acid as a green corrosion inhibitor on the surface of stainless steel 410

Fifteen percent hydrochloric acid (HCl) solutions are used for some cleaning processes in the petroleum industry. The use of such a corrosive medium is mainly responsible for the corrosion of the stainless steel (SS-410) vessels and pipings. In this study, the corrosion inhibiting properties of Oryza sativa plant extract (OSPE) from agricultural residues are investigated on SS-410 steel surfaces in a 15% HCl medium. Gravimetric analysis showed a maximum corrosion inhibition of 91.92% with 4 g/L OSPE in 15% HCl solution. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction studies confirmed the adsorption of OSPE on the SS-410 surface. The adsorption of OSPE on SS-410 followed the Langmuir adsorption isotherm, indicating the formation of a monolayer on the SS-410 surface. The theoretical study confirmed that the anticorrosive effect could be mainly related to the phytochemical 9,12,15-octadecatrienoic acid 2,3-dihydroxypropyl ester. Consequently, the OSPE containing this phytochemical shows an anticorrosive behavior on the SS-410 surface in an acidic 15% HCl solution.