Experimental study of inhibitor containing sulfur for mild steel in hydrochloric acid

2016 ◽  
Vol 63 (4) ◽  
pp. 275-280
Author(s):  
Yao Ding ◽  
Zhengtang Luo ◽  
Dong Liu

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.

2014 ◽  
Vol 61 (5) ◽  
pp. 300-306 ◽  
Author(s):  
B.P. Markhali ◽  
R. Naderi ◽  
M. Sayebani ◽  
M. Mahdavian

Purpose – The purpose of this paper is investigate the inhibition efficiency of three similar bi-cyclic organic compounds, namely, benzimidazole (BI), benzotriazole (BTAH) and benzothiazole (BTH) on carbon steel in 1 M hydrochloric acid (HCl) solution. Organic inhibitors are widely used to protect metals in acidic media. Among abundant suggestions for acid corrosion inhibitors, azole compounds have gained attention. Design/methodology/approach – The inhibition efficiency of the three organic compounds was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Findings – Superiorities of BTH and BTAH corrosion inhibitors were shown by EIS data and polarization curves. Moreover, the results revealed that BTAH and BTH can function as effective mixed-type adsorptive inhibitors, whereas no inhibition behavior was observed for BI. Both BTAH and BTH obeyed Longmuir adsorption isotherm. The results obtained from this isotherm showed that both inhibitors adsorbed on the specimen surface physically and chemically. The difference in inhibition efficiencies of BTAH, BTH and BI was related to the presence of nitrogen and sulfur hetero atoms on their molecular structures. Originality/value – This study evaluated inhibition efficiency of BI, BTAH and BTH using electrochemical methods. In addition, the study attempted to find inhibition mechanism of the inhibitors and to find modes of adsorption of the inhibitors, correlating effects of heteroatoms and inhibition efficiency.


2018 ◽  
Vol 65 (1) ◽  
pp. 1-10
Author(s):  
Daoiya Zouied ◽  
Emna Zouaoui ◽  
Mohamed Salah Medjram ◽  
Olfa Chikha ◽  
Karima Dob

Purpose Corrosion and corrosion inhibition of alloyed zinc electrode were investigated in neutral chloride solution using electrochemical techniques. The purpose of this study is to study the corrosion inhibition of acetanilide and para hydroxy acetanilide as organics inhibitors for corrosion control of alloyed zinc electrode in NaCl 3 per cent solution. Design/methodology/approach A volt lab PGZ 301, assembled using alloyed zinc working electrode, a platinum counter electrode and a saturated calomel electrode as the reference electrode, was used in the experiment. This research was conducted using potentiodynamic polarization and electrochemical impedance spectroscopy techniques. Findings Acetanilide, para hydroxy acetanilide and their mixture provided inhibitions efficiencies of 88 per cent at 40 ppm, 87 per cent with 80 ppm and 99.86 per cent with (40 ppm AC + 80 ppm PHA), respectively. The study also discusses the corrosion inhibition mechanism of the protective layers. The adsorption of acetanilide and para hydroxy acetanilide on metal surface obeyed Langmuir’s adsorption isotherm. Polarization measurements showed that the acetanilide and the para hydroxy acetanilide, and their mixture acted as cathodic inhibitors in NaCl solution, and the inhibitor molecules followed physical adsorption on the surface of alloyed zinc. Originality/value The other new inhibitors which are very efficient inhibitors and to be applied in the field of prevention and control against corrosion.


2014 ◽  
Vol 43 (5) ◽  
pp. 299-313 ◽  
Author(s):  
S.A. Umoren ◽  
U.M. Eduok ◽  
M.M. Solomon

Purpose – The purpose of this paper is to investigate the effect of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and blended formulations on the corrosion inhibition of aluminium in HCl solutions at 30-60°C and to study the mechanism of action. Design/methodology/approach – The inhibitive effect of the homopolymers and polymer blend was assessed using weight loss and hydrogen evolution methods at 30 and 60°C. The morphology of the corroding aluminium surface without and with the additives was visualized using atomic force microscopy. The trend of inhibition efficiency with temperature was used to propose the mechanism of inhibition and type of adsorption. Findings – Results obtained show that inhibition efficiency (η%) increases with increase in concentration of the polymers but decreases with increase in temperature. The inhibition efficiency of the homopolymers and their blends decreased with rise in temperature. Inhibition efficiency was found to be synergistically enhanced on blending the two homopolymers with highest inhibition efficiency obtained for (PEG:PVP) blending ratio of 1:3. The phenomenon of physical adsorption is proposed from the trend of inhibition efficiency with temperature. Research limitations/implications – The mechanistic aspect of the corrosion inhibition can be better understood using electrochemical studies such as potentiodynamic polarization and electrochemical impedance spectroscopy. Originality/value – Studies involving the use of polymer blends/mixtures as corrosion inhibitor for metals in corrosive environments are scarce. The results suggest that the mixture could find practical application in corrosion control in aqueous acidic environment. The data obtained would form part of database on the use of polymer–polymer mixtures to control acid-induced corrosion of metal.


2014 ◽  
Vol 43 (3) ◽  
pp. 127-138 ◽  
Author(s):  
Aida Zaabar ◽  
Razika Aitout ◽  
Laid Makhloufi ◽  
Kamel Belhamel ◽  
Boualem Saidani

Purpose – The aim of this research was to investigate the use of aqueous extracts of nettle plant (NE) as a green corrosion inhibitor of mild steel in hydrochloric acid solution. Design/methodology/approach – The inhibition efficiency was investigated by weight loss measurements, potentiodynamic polarizations, electrochemical impedance spectroscopy, SEM observations and EDX analysis. Findings – The inhibition efficiency increased with an increase in concentration of NE up to a critical concentration of 1.5×10−3 g · cm−3 where the highest inhibition efficiency of 97 percent was obtained. The adsorption of the inhibitor was spontaneous (reflected by the negative value of ΔGads0), supported the mechanism of physical adsorption and obeyed to the Langmuir adsorption isotherm. The inhibition action of the extracts was independent on the storage time; it could be conserved without any specific conditions of time and temperature. Research limitations/implications – The anticorrosion effect can be better understood when the active compound in the extracts is identified and what is the inhibition efficiency of one component in the presence of another in the mixture (synergetic or antagonist effects). Practical implications – Nettle is a healthy plant, without particular toxicity that can find possible applications as environmentally friendly inhibitor of mild steel used as materials in food industry. Originality/value – Aqueous nettle extracts were studied for the first time as corrosion inhibitor and its anticorrosion effect was proven by standard methods.


2019 ◽  
Vol 66 (5) ◽  
pp. 573-582
Author(s):  
Yanhua Zhu ◽  
Liqiang Zhao ◽  
Pingli Liu ◽  
Xiao Qu

Purpose In this work, a kind of Mannich base (C21H25NO) was synthesized with cinnamal aldehyde, acetophenone and diethylamine in a condensing reflux device based on the conventional method. Optimization of the inhibitor concentration was explored. Design/methodology/approach Spectral properties of this compound was investigated by FTIR, and its inhibition efficiency and mechanism on N80 steel in 20% hydrochloric acid solution were studied by weight loss measurement, electrochemical measurement (potentiodynamic polarization and electrochemical impedance spectroscopy) and surface analytical measurement (scanning electron microscope with energy dispersive spectrometer). Findings The results showed that the new inhibitor reduced the double-layer capacitance and increased the charge transfer resistance. The inhibition efficiency is 99.7% when the concentration of C21H25NO is 3%. The adsorption of C21H25NO on N80 steel surface in 20% HCl solution was found to be spontaneous and steady. Observed from the steel surface, an inhibition film was confirmed to be presented after adding inhibitor and successfully hindered the corrosive ions from reaching the bulk steel. Originality/value A new Mannich base (C21H25NO) was synthesized by cinnamal aldehyde, acetophenone and diethylamine for the corrosion prevention of N80 steel in 20% hydrochloric acid solution.


2017 ◽  
Vol 64 (4) ◽  
pp. 409-417 ◽  
Author(s):  
Hamza Bentrah ◽  
Abdelouahad Chala ◽  
Mounir Djellab ◽  
Youssouf Rahali ◽  
Hicham Taoui

Purpose This paper aims to investigate the influence of temperature (25-65°C) on the adsorption and the inhibition efficiency of gum arabic (GA) for the corrosion of API 5L X42 pipeline steel in 1M HCl. Design/methodology/approach Inhibition behaviour on steel in HCl has been studied in relation to the concentration of the inhibitor and the temperature using potentiodynamic polarization curves and electrochemical impedance spectroscopy. Thermodynamic parameters of adsorption were calculated from the viewpoint of adsorption theory. Findings The results show that at a temperature range from 25 to 65°C, GA was a good inhibitor for API 5L X42 pipeline steel, and its inhibition efficiency was significantly stable. The maximum inhibition efficiency (93 per cent) is obtained at 4 g L−1. In absence and presence of GA, there is almost no change in the corrosion mechanism regardless of the temperature. The adsorption of GA on steel surface is an exothermic process. The adsorption of GA involves physical adsorption. Practical implications The use of GA as an eco-friendly corrosion inhibitor is practical for carbon steel in HCl. Originality/value The stability of inhibition efficiency of GA at a temperature range from 25 to 65°C could find possible applications in acid pickling, industrial acid cleaning and acid descaling.


2018 ◽  
Vol 65 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Ayssar Nahle ◽  
Fadoua El-Hajjaji ◽  
Abdeslam Ghazoui ◽  
Nour-Eddine Benchat ◽  
Mustapha Taleb ◽  
...  

Purpose The purpose of this paper is to study the inhibition effect of (6-phenyl-3-oxopyridazin-2-yl) acetohydrazide (GP4) on the corrosion of mild steel in acidic medium by gravimetric measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Design/methodology/approach Weight loss measurements, potentiodynamic tests and EIS were performed during this study. Findings (6-phenyl-3-oxopyridazin-2-yl) acetohydrazide (GP4) was found to be a very efficient inhibitor for mild steel in 1.0 M HCl solution, reaching about 85 per cent with inhibitor concentration 1.0 × 10-3 M at 303 K. Practical implications (6-phenyl-3-oxopyridazin-2-yl) acetohydrazide (GP4) was found to play an important role in the corrosion inhibition of mild steel in acidic solution. Originality/value This paper is intended to be added to the family of pyridazine derivatives which are highly efficient inhibitors and can be used in the area of corrosion prevention and control.


2018 ◽  
Vol 14 (4) ◽  
pp. 934-949
Author(s):  
Husna Siraji Nyambia ◽  
Hamdino Hamdan

Purpose This study extensively aims to investigate the effects of different aspects of corporate governance (CG) mechanism, including board size, executive directors’ shareholdings, Chief Executive Officer (CEO) duality, a family member as the CEO and/or chairperson of the board, independent directors in remuneration committee and number of board meeting, on executive directors’ remuneration in small firms listed on Bursa Malaysia (BM). Design/methodology/approach The sample of this study consists of 173 bottom-listed companies from Bursa Malaysia in Year 2010. The Year 2010 was chosen because the disclosure of remuneration committee activities and directors’ pay structure is required under the revised Malaysia Code of Corporate Governance, 2007. Furthermore, the period selected is after the global economic crisis (2008), which may have an effect on the remuneration structure in small firms. The ordinary least squares regression was used to estimate the relationship between remuneration as dependent variable and other independent variables. Findings A finding from this study reveals that there is a significant positive relationship between executive ownership and executive remuneration, and between board size and executive remuneration. The results provide evidence that the family members manipulate power and control remuneration in small firms. This indicates that the independent directors are not truly independent to monitor and control the firm activities, including minimizing the excessive remuneration. Research limitations/implications This study examines how the corporate governance (CG) affects remuneration among 173 small firms in Malaysia based on market capitalization, for one year, 2010. Hence, the results may not be generalizable to other periods or types of the companies. This shows the possibility of the absence of some additional variables in the research model and hence a limitation to the findings of the study. Although the study is being parsimonious in the choice of relevant variables, prior literature serves the guide in the selection of the used variables. This therefore gives room for future research using the potential omitted variables. Furthermore, the study focuses on total remuneration, such as fees, salaries, bonuses and benefits in kind, which makes aggregate directors’ remuneration. However, this study did not consider the remuneration related to stock options. Finally, this study only uses secondary data; hence, it could be interesting to use other instruments to collect data like a questionnaire to add more weight to the research. This study only uses one-year data; therefore, impact of changes between years cannot be analysed. Originality/value Results of the study provide evidence that the family members manipulate power and control remuneration in small firms. They reduce the effectiveness of non-executive directors because most of them are appointed by a family member and not socially responsible to their stakeholders.


2019 ◽  
Vol 66 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Walid Belmaghraoui ◽  
Aimad Mazkour ◽  
Hicham Harhar ◽  
Mourad Harir ◽  
Souad El Hajjaji

Purpose This study aims to investigate the corrosion inhibition effect of extracted oil from Ziziphus lotus fruit on corrosion of C38 carbon steel in 5.5 M H3PO4 solution using potentiodynamic polarization and impedance techniques. Design/methodology/approach Oil composition was determined using gas chromatography, and the results showed that oleic and palmitic acids present approximately 84.0 per cent of its total chemical content. Electrochemical impedance spectroscopy (EIS) data were analyzed by adapting it to a well-developed electric circuit model. The inhibition efficiency of Z. lotus oil was calculated and compared using Tafel polarization and EIS. Findings Accordingly, the oil extract was found to act as an anodic type inhibitor. Furthermore, inhibition efficiency of Z. lotus oil extract increase with oil concentrations and achieve approximately 70.5 per cent at 3 g/L solution of Z. lotus oil. Originality/value The results obtained from different tested methods were in line, and the oil was able to reduce significantly the kinetics of the corrosion process of C38 carbon steel.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
J. Ishwara Bhat ◽  
Vijaya D. P. Alva

The corrosion inhibition of mild steel by miconazole nitrate, an antifungal drug has been investigated using potentiodynamic polarization, electrochemical impedance spectroscopy technique, and weight loss methods. The experimental results suggested miconazole nitrate is a good corrosion inhibitor for mild steel in 1 M hydrochloric acid medium. The inhibition efficiency increased with increase in inhibitor concentration. The thermodynamic parameters were determined and discussed. The inhibition was assumed to occur via adsorption of the inhibitor molecule on the surface of mild steel following Langmuir adsorption isotherm.


Sign in / Sign up

Export Citation Format

Share Document