Synthesis and investigations of heterocyclic compounds as corrosion inhibitors for mild steel in hydrochloric acid

Abstract

The corrosion inhibition of mild steel in 0.5 M hydrochloric acid by six synthesized heterocyclic compounds was studied using weight loss measurements. The inhibition efficiency exceeded 95%. The excellent inhibitor performance was attributed to the formation of protection adsorption films on the steel surface. The structures of compounds were confirmed by Fourier transform infrared and nuclear magnetic resonance analysis. The adsorption of inhibitor on steel surface followed the Langmuir adsorption isotherm. Quantum chemical calculations were also adopted to clarify the inhibition mechanism.

Performance of Synthesized Acetone Based Inhibitor on Low Carbon Steel Corrosion in 1 M HCl Solution

“…This agrees with assumption of chemical adsorption of POTA molecules on metal surface. These results agree with many researches [17,19,25]. Enhance in inhibitor performance with temperature is apparently due to an increase in the chemisorption of the POTA.…”

“…In our previous work [17], six heterocyclic compounds were synthesized and tested as corrosion inhibitors for mild steel in 0.5 M HCl. The inhibition efficiency was more than 95%.…”

Synthesis of ZnO-NPs Using a Convolvulus arvensis Leaf Extract and Proving Its Efficiency as an Inhibitor of Carbon Steel Corrosion

“…Figure 4 illustrates the potentiodynamic polarization curves for both the anodic and cathodic Tafel behavior of carbon steel corrosion in 1 M HCl in the absence and presence of different concentrations of the inhibitor at temperatures of 298 and 333 K. The Tafel slopes show that the addition of an inhibitor influences both anodic and cathodic reactions, leading to the conclusion that the effect of ZnO-NPs inhibitors is of a mixed type. A clear displacement of the Tafel anodic and cathodic curves has been observed for increases in ZnO-NPs concentration to 0.06 mg/mL and above, at which point the inhibition effect plateaus due to saturation of the carbon steel surface with inhibitor molecules [27]. It should be noted that as the concentration of the inhibitor increased, the rate of corrosion decreased.…”

“…This means that the inhibitor has a high efficiency of 91% at a concentration of 0.12 mg/mL at 298 K, as recorded in Table 2. The high temperature increased i corr [28], but the effect of the inhibitor remained the same at a temperature of 298 K. Its effect at 333 K almost became constant above ZnO-NPs concentrations of 0.06 mg/mL, showing that even at high temperatures [27], when the surface of the electrode is saturated with inhibitor molecules [29], the inhibition mechanism remains functional. The presence of ZnO-NPs, in addition to the molecules of the Convolvulus arvensis leaf extract on the carbon steel surface, form a protective layer that limits anodic and cathodic reactions and thus reduces the rate of corrosion [18].…”

Coumarins into Polyurethanes for Smart and Functional Materials

“…Potential improvement in anticorrosive properties from coumarin additives was studied by evaluating blistering, scribe failure and the degree of rusting on painted steel panels after performing a salt spray (fog) test for 500 h of exposure. Organic heterocyclic compounds are considered organic structures with some effective corrosion inhibition properties [137]. Therefore, synthesised coumarin derivatives were expected to be alternative organic inhibitors for corrosion protection.…”