Search

Purpose: This study aims to prevent mild steel (MS) against corrosion in 0.5 M HCl solution, 2-amino-4-methoxy-6-methyl-1,3,5-triazine was used. The effectiveness of the compound as a corrosion inhibitor was studied via electrochemical, surface and theoretical calculation techniques. Design/methodology/approach: For concentrations ranging from 0.5 to 10.0 mM, almost similar polarization resistances were obtained from electrochemical impedance spectroscopy (EIS) and linear polarization resistance tests. It also investigated inhibitive activity of 2-amino-4-methoxy-6-methyl-1,3,5-triazine on the steel surface using scanning electron and atomic force microscope instruments. Langmuir adsorption is the best matched isotherm for the adsorption of the inhibitor to the steel surface. Findings: EIS method was used to determine inhibition efficiency, which was determined to be 95.7% for 10.0 mM inhibitor containing acid solution. Density functional theory's predictions for quantum chemistry agreed well with the other experimental results. Originality/value: The methods used in this study are effective and applicable; the used organic inhibitor is 2-amino-4-methoxy-6-methyl-1,3,5-triazine; and protective effectiveness is important, which is crucial for the task of MS corrosion prevention. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate cimetidine as corrosion inhibitor of aluminium in hydrochloric acid medium. Design/methodology/approach: Cimetidine was characterized by gas chromatography mass spectrophotometer and Fourier transform infrared spectroscopy to determine its chemical composition and functional groups, respectively. Gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopic techniques were used in the corrosion inhibition process. Thermodynamic and adsorption parameters were evaluated. And response surface methodology was used to optimize the corrosion inhibition process. Findings: Analysis of the results revealed that major constituents of cimetidine include metronidazole, n-hexadecanoic acid cyclohexane and methyl ester. It has C-H stretch, C = N stretch, CH3C-H bend, ring C = C stretch, -C-O-O stretch, N-H bend, C-O stretch and C-H bend as predominant functional groups. Adsorption of molecules of the inhibitor on the aluminium surface was spontaneous, and it followed mechanism of physical adsorption. Response surface methodology revealed that quadratic model adequately described the inhibition efficiency of cimetidine as function of inhibitor concentration, temperature and time. Chemical and electrochemical results are in agreement that the cimetidine is a viable corrosion inhibitor. Cimetidine was revealed as mixed-type inhibitor because it controlled both cathodic and anodic reactions. Originality/value: Empirical and optimization studies of cimetidine drug as corrosion inhibitor of aluminium in hydrochloric acid medium were carried out. The research results can provide the basis for deploying drugs (with mucosal protective and antacid properties) for corrosion control of metallic structures. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely, 1-((1-((2,2,7,7-tetramethyltetrahydro-5H-bis([1,3]dioxolo)[4,5-b:4′,5′-d]pyran-5-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazole (TTB) on the corrosion of mild steel in aerated 1 M H2SO4. Design/methodology/approach: The authors have used weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy, FT-IR studies, scanning electron microscopy analysis and energy dispersive X-ray (EDX) spectroscopy techniques. Findings: It is found that, in the working range of 298-328 K, the inhibition efficiency of TTB increases with increasing concentration to attain the highest value (92 per cent) at 2.5 × 10−3 M. Both chemisorption and physisorption of TTB take place on the mild steel, resulting in the formation of an inhibiting film. Computational methods point to the imidazole and phenyl ring as the main structural parts responsible of adsorption by electron-donating to the steel surface, while the triazol ring is responsible for the electron accepting. Such strong donating–accepting interactions lead to higher inhibition efficiency of TTB in the aqueous working system. Originality/value: This work is original with the aim of finding new acid corrosion inhibitors. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to study the corrosion inhibition of Methyl 2-(benzamido)-2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate (MBPTA) and Methyl 2-(benzamido)-2-(4-p-tolyl-1H-1,2,3-triazol-1-yl) acetate (MBTTA) in 1 M H2SO4 solution at 25 °C. Design/methodology/approach: The authors have used weight loss measurements, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, FT-IR, quantum chemical calculations and scanning electron microscopy (SEM) techniques. Findings: The polarization measurements indicate that both compounds are mixed type inhibitors, and that MBTTA is more effective than MBPTA. The effect of temperature on the corrosion behavior using optimal concentration of MBTTA and MBPTA was studied in the temperature range 298-328 K. SEM was used to examine the morphology of the metal surface. Thermodynamic parameters were calculated and discussed. Monte Carlo simulations were applied to lookup for the most stalls configuration and adsorption energy for the interaction of inhibitors on Fe (1 1 1) interface. The difference in inhibition efficiencies between the two organic inhibitors can be clearly explained in terms of frontier molecular orbital theory. Originality/value: The authors report on the comparative inhibiting effect of two new 1,4-disubstituted 1,2,3-triazoles, namely Methyl 2-(benzamido)-2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate (MBPTA) and Methyl 2-(benzamido)-2-(4-p-tolyl-1H-1, 2, 3-triazol-1-yl) acetate (MBTTA) on mild steel corrosion in 1 M H2SO4 solution. [ABSTRACT FROM AUTHOR]

Purpose This paper aims to study inhibitory effect of 4-aminothiophenol on the corrosion of mild steel (MS) in 0.5 M HCl.Design/methodology/approach In this study, electrochemical experiments, quantum chemical calculations, potentiodynamic measurements, linear polarization resistance and scanning electron microscopy were used.Findings The experimental results suggest that this compound is efficient corrosion inhibitor and the inhibition efficiencies increase with increasing their (from 0.5 to 10.0 mM.) concentrations. This reveals that inhibitive actions of inhibitors were mainly due to adsorption on mild steel surface. The adsorption of these inhibitors was found to obey Langmuir adsorption model. The computed quantum chemical features show good correlation with empirical inhibition efficiencies.Originality/value The 4-aminothiophenol is suitable inhibitor for application in closed-circuit systems against corrosion. The study is original and has great impact in industrial area. The obtained theoretical results have been adapted with the experimental data. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this study is to compare the inhibitive effect of polyaniline (PAni) and N-cetyl-N,N,N trimethyl ammonium bromide (CTAB)-stabilized PAni in a hydrochloric acid (HCl) medium.Design/methodology/approach PAni has been deposited potentiodynamically on mild steel in the presence of CTAB as a stabilizing agent to achieve high corrosion inhibition performance by the polymer deposition. The corrosion inhibition studies of CTAB-stabilized PAni inhibitor in 0.1 M HCl acidic solution was carried out by electrochemical methods, namely, open-circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy technique.Findings The results of electrochemical studies have shown that the CTAB-stabilized PAni inhibitor has higher corrosion efficiency than PAni on mild steel in 0.1 M HCl solution. The maximum per cent efficiency evaluated using the potentiodynamic polarization method is approximately 91.9.Originality/value CTAB-stabilized PAni has never been studied as a corrosion inhibitor for mild steel in an acidic medium. The investigations demonstrate relatively the better corrosion inhibition efficiency and high dispersion of the polymer in the acidic medium. [ABSTRACT FROM AUTHOR]

Purpose This paper aims to evaluate the inhibitive action of different concentrations of Sesbania grandiflora leaf extract on the mild steel corrosion in an aggressive HCl medium under different experimental conditions.Design/methodology/approach Weight loss investigation, open-circuit voltage analysis, Tafel polarisation, AC impedance analysis, etc. were used for the evaluation of inhibition efficiency. The influence of immersion period on inhibition efficiency was evaluated. The mechanism of action of the inhibitor is also discussed. Infrared (IR) spectroscopy and energy-dispersive X-ray spectroscopy analysis were used to characterise the passive film.Findings The results suggested that 10,000 ppm solution has maximum inhibition efficiency of 98.01 per cent at room temperature, while 1,000 ppm solution also exhibited a better efficiency of about 96.16 per cent. Efficiency of inhibitor solution was found to increase with an increase in its concentration. Polarisation study proposed the solution as an anodic inhibitor. Impedance study confirmed the formation of a protective layer over the surface of the specimen, and the constituents of the film were identified using IR spectroscopy. Stability of the film adsorbed on the steel was cleared from the steady open-circuit potential value. Study on action of the inhibitor under accelerated conditions revealed the fact that the efficiency of extract in preventing corrosion is good under stimulated conditions also.Practical implications The action of inhibitor sustains for a sufficient time period and could sustain under stimulated conditions. Hence, its application is practically possible in industries. The proposed inhibitor is widely available and is environmentally safe.Originality/value HCl is an industrially important chemical used for acid cleaning, acid pickling, etc. HCl was used as an aggressive corrosion environment. As the chances for mild steel to be in contact with HCl were very high, it was important to develop an efficient, economical and eco-friendly inhibitor for corrosion. [ABSTRACT FROM AUTHOR]

Purpose Surfactants have been reported to have high inhibition efficiencies for corrosion of steel. This paper aims to study the performance of a low toxic copolymer of polydimethylsiloxane and polyoxyalkylene (POA) surfactant named as POPS, as a corrosion inhibitor for mild steel (ASTM 1005) in hydrochloric acid (HCl) solution at 25°C.Design/methodology/approach To evaluate POPS efficiency as a corrosion inhibitor, the following techniques were used: surface tension measurements, weight loss measurements, open circuit potential monitoring, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy and contact angle measurements.Findings Results indicated that POPS acted as a mixed corrosion inhibitor and led to a hydrophobic protector film on the metal surface. The adsorption process obeyed the Langmuir adsorption isotherm by chemisorption. The maximum efficiency of the surfactant studied was achieved in a concentration around the critical micelle concentration.Originality/value Surfactant (POPS) of low level of toxicity acts as a mixed corrosion inhibitor in HCl medium. Inhibitor film formation was characterized by EIS results. A mechanism for corrosion inhibition is proposed. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this paper is to use Dextrofosfomysin levophenethylamine salt to prepare HEHSPN-(Na)2 (HSPN), a new corrosion inhibitor containing sulfur.Design/methodology/approach The inhibition efficiency for Q235 steel in hydrochloric acid has been evaluated by weight-loss test, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Surface studies were performed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).Findings The results show that inhibition efficiency of HSPN increases with an increase in concentration. Adsorption conforms to Flory–Huggins uniform temperature equation, which is multi-molecular layer adsorption and belongs to physical adsorption.Originality/value This paper is intended to be added to the family of papers that deal with green corrosion inhibitors which are highly efficient and can be used in the area of corrosion prevention and control. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this paper is to evaluate the inhibitive effect of a polyaniline copolymer, namely, poly(aniline-co-o-anthranilic acid) solution, on the corrosion of carbon steel in hydrochloric acid. The effect of the different concentrations of the corrosion inhibitor also was investigated. Design/methodology/approach - Fourier transform infrared spectroscopy was used to characterise the polyaniline copolymer. Weight loss measurements, potentiodynamic polarization and electrochemical impedance spectroscopy were carried out to determine the corrosion inhibition efficiency. Scanning electron microscopy was used to observe the morphology of the corroded surface. Findings - The results indicated that polyaniline copolymer solution acts as an effective corrosion inhibitor for carbon steel in hydrochloric acid solution and that the adsorption of the compound on the metal surface obeys the Langmuir adsorption isotherm. Practical implications - The corrosion inhibitor could have wide applications in the acid washing industry to reduce the corrosion rate of carbon steel in hydrochloric acid. Originality/value - This paper reveals a new type of corrosion inhibitor prepared from a polyaniline copolymer. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this paper is to study electrochemically and by weight loss experiments the effect of 4-vinylbenzyl triphenyl phosphonium chloride on the corrosion inhibition of mild steel in 1.0?M HCl solution, which will serve researchers in the field of corrosion. Design/methodology/approach - Electrochemical and weight loss measurements were carried out on carbon steel specimens in 1.0?M HCl and in 1.0?M HCl containing various concentrations (1.0?×?10-7 to 1.0?×?10-4?M) of the laboratory synthesized 4-vinylbenzyl triphenyl phosphonium chloride at temperatures ranging from 303 to 343?K. Findings - 4-vinylbenzyl triphenyl phosphonium chloride was found to be a highly efficient inhibitor for carbon steel in 1.0?M HCl solution, reaching about 99 per cent at the concentration of 1?×?10-4?M at room temperature and about 96 per cent at 303?K, a concentration and temperature considered to be very moderate. The percentage of inhibition in the presence of this inhibitor was decreased with temperature which indicates that physical adsorption was the predominant inhibition mechanism because the quantity of adsorbed inhibitor decreases with increasing temperature. Practical implications - This inhibitor could have application in industries, where hydrochloric acid solutions at elevated temperatures are used to remove scale and salts from steel surfaces, such as acid cleaning of tankage and pipeline, and may render dismantling unnecessary. Originality/value - This paper is intended to be added to the family of phosphonium salt corrosion inhibitors which are highly efficient and can be employed in the area of corrosion prevention and control. [ABSTRACT FROM AUTHOR]