2,4-dihydroxybenzaldehyde based Schiff base derivatives as an effective corrosion inhibitor for steel corrosion in 1 M hydrochloric acid solution

Abstract

The present research is centered on Schiff base derivatives such as 4-((hexylimino)methyl)benzene-1,3-diol (HIMB) and 4,4′-((1E,1′E)-(hexane-1,6-diylbis(azaneylylidene))bis(methaneylylidene))bis(benzene-1,3-diol) (HAMB). FTIR and 1H NMR were used to determine the structure of the produced Schiff base compounds. Furthermore, gravimetric and electrochemical methods were used to investigate the efficacy of these compounds to suppress corrosion of carbon steel oil well pipes in filtered formation water solution containing 1 M hydrochloric acid. Experiments at various concentrations allowed us to assess HIMB and HAMB's inhibitory efficacy and adsorption behavior. The investigated inhibitors become further active at preventing as concentration increases. The potentiodynamic polarization investigation found that HIMB and HAMB both inhibit cathodic and anodic processes. Affording to impedance (EIS) information, the charge transfer resistance (Rct) increases when HIMB and HAMB concentrations grow. Adsorption of investigated inhibitors at the carbon steel according to Langmuir isotherm model was measured using gravimetric measurements. The presence of a membrane of HIMB and HAMB inhibitors on top of the carbon steel surface of oil well pipes was supported by theoretical data as well as experimental tests.