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The effects of the addition of poly(4‐vinylpyridine) (P4VP) and its derivative poly(4‐vinylpyridine poly‐3‐oxide ethylene) (P4VPPOE) on the corrosion of Cu60‐Zn40 in 0.5M HNO₃ have been investigated by potentiodynamic and weight loss measurements. Both of the studied polymers decrease the corrosion rate. Their inhibition efficiency (E%) increases with the concentration. The maximum of inhibition was obtained for P4VPPOE (100 per cent at 10^–5M). E% obtained from cathodic Tafel plots and weight loss methods were in good agreement. The inhibitors were adsorbed on the Cu60‐Zn40 surface according to the Frumkin adsorption isotherm model. P4VPPOE acts as a cathodic inhibitor and its efficiency is temperature independent.

The purpose of this study was to examine the copper protection against corrosion using 3-thiophenemalonic acid (3TMA).

The heterocyclic organic molecule was tested experimentally as a corrosion inhibitor of copper in two different concentrations (0.01 M and 0.001 M) in 0.5 M solutions of sodium chloride and sulfuric acid by AC electrochemical and DC techniques.

Results showed that the organic compound was adsorbed chemically on the copper surface, and the inhibitions mechanism was both anodic and cathodic. The corrosion mechanism was under mixed control: charge transfer from metal to the environment through the double electrochemical layer, and diffusion processes.

This inhibitor could have application in water cooling systems.

The results of this paper showed that 3TMA could be used for reducing corrosion rates of copper in solutions of sodium chloride and sulfuric acid.

The purpose of this paper is to study the corrosion inhibition of carbon steel (CS) using a “green” inhibitor, polyvinyl pyrrolidone (PVP), in an aerated, alkaline medium containing 0.1M NaCl (blank) at pH 9 and pH 10. The effects of some additives, such as KI and untreated Saudi clay (UC) were investigated.

Weight loss method, surface studies, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation were applied.

The inhibition efficiencies of blank solutions with 1000 ppm PVP ranged from 66‐78% for weight loss results and from 23‐66% for the electrochemical tests. The EIS results indicated that the adsorption of PVP led to the formation of a protective film on the metal/solution interface. Tafel results indicated that PVP is a mixed‐type inhibitor. The addition of KI to PVP and the blank solution significantly increased inhibition efficiency, while the addition of UC reduced the inhibition efficiency. Adding KI resulted in a high surface‐area coverage ranging from about 91% after one hour to about 81% after 45 hours. The adsorption mechanism was fitted with a Langmuir isotherm.

This is a static study, whereas in oil drilling there is a dynamic system; however the findings may apply to both systems.

Carbon steel is used in alkaline and neutral media in the petroleum industry. The effect of KI additives was examined.

The paper shows how it may be possible to reduce the cost of repair of equipment and lower the environmental impact of corrosion.

There are few studies which investigate the combining effect of polymer and KI in alkaline medium containing NaCl.

The purpose of this paper is to carry out laboratory studies of the inhibition effect of tyrosine (Tyr) on the corrosion of low chromium alloy steel (ASTM A213 grade T22) in 7 wt percent sulfamic acid solutions.

The corrosion inhibitive effect of Tyr was investigated using electrochemical impedance spectroscopy (EIS) and the new technique electrochemical frequency modulation (EFM).

It was found that the inhibition efficiency increased with increasing inhibitor concentration, while a decrease was detected with the rise of temperature and stirring speed. The corrosion inhibition is due to physical adsorption of Tyr on the steel surface. Adsorption of the inhibitor molecule, onto the steel surface follows the Temkin's adsorption isotherm.

The obtained results from both methods (EIS and EFM) at different experimental conditions were in high agreement and almost similar. This is an indication that the EFM technique can be used efficiently for monitoring the corrosion inhibition under the studied conditions.

The purpose of this investigation is the evaluation of the inhibitive performance of a new “gemini” surfactant in the series of bis‐quat: N, N, N′, N″, N″‐pentamethyl diethyleneamine‐N, N″‐di‐[tetradecylammonium bromide] on the corrosion of iron in 1 M HCl by gravimetric, potentiodynamic and electrochemical impedance measurements. The effect of the temperature on the corrosion behavior of iron in 1 M HCl without and with inhibitor is studied in the temperature range (298‐333 K). This work also attempts to correlate thermodynamic and kinetic parameters with the inhibition effect.

The inhibition efficiency of gemini synthesized is investigated by weight loss, potentiodynamic polarization and impedance spectroscopy methods.

The synthesized gemini bis‐quat acted as a good inhibitor in 1 M HCl, and inhibition efficiency increased with inhibitor concentration and temperature. Polarization curves showed that the surfactant was a mixed‐type inhibitor in hydrochloric acid. Impedance spectroscopy measurements showed that the inhibitor acted through the formation of a multilayer film at the iron surface. The adsorption of inhibitor on the iron surface obeyed the Langmuir adsorption isotherm equation. The inhibition effect was satisfactorily explained by both thermodynamic and kinetic parameters.

The adsorption of surfactants in the metal surface can markedly change the corrosion resisting property of the metal. So the study of the relation between the adsorption and corrosion inhibition is of a great importance. This was the first attempt to study the inhibition properties of gemini surfactants at the host laboratory.

To investigate the effect of halide ions on the corrosion inhibition of mild steel using polyvinyl alcohol (PVA) in H₂SO₄ at 30‐60°C and to study the mechanism of action.

The corrosion rates were determined using the gravimetric (weight loss) and gasometric (hydrogen evolution) techniques. The results obtained in the absence and presence of PVA, halides, PVA – halides combination were used to calculate the inhibition efficiency (%I), degree of surface coverage and to propose the mechanism of inhibition and type of adsorption.

Results obtained showed that inhibition efficiency (%I) increased with the increase in concentration of PVA, on the addition of halides and with the increase in temperature. Phenomenon of chemical adsorption was proposed and PVA was found to obey Langmuir, Flory‐Huggins and Freundlich adsorption isotherms. The synergism parameter, S₁, evaluated was found to be greater than unity and the values of E_a, ΔH°, ΔS° and ΔG° obtained revealed that the adsorption process was spontaneous.

Electrochemical studies such as polarization and AC impedance spectra will enlighten more on the mechanistic aspects of the corrosion inhibition and more polymers need to be evaluated as corrosion inhibitors.

PVA can be used as corrosion inhibitor and the addition of halides to PVA improves the inhibition efficiency considerably.

This paper provides new information on the effects of halides on the corrosion inhibition using PVA as an inhibitor for mild steel in acidic medium. Such a study had not been reported elsewhere.