ISSN 2305-6894

2018, Vol. 7, Issue 2 (pp. 112-270)

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Assessment of inhibiting features of some commercial bactericides

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1 Gasprom VNIIGAZ, Proektiruemiy proezd 5537, vlad. 15, str. 1, Razvilka village, 142717Moscow region, Russia
2 Gasprom PJSC, 16 Nametkina St., 117997Moscow, Russia
3 Gubkin Russian State University of Oil and Gas, 65 Leninsky Prospekt, 119991 Moscow, Russia

Abstract: The study deals with bacteriological and anti-corrosion features of three domestic bactericidal corrosion inhibitors (CI) in presence of sulphate-reducing bacteria in an oxygen-depleted and CO2-containing nutritent medium. Efficacy of compositions under study in both inhibiting bacterial growth in an environment and decreasing total corrosion rate in structural steel was measured experimentally. Particular attention in discussion of results was paid to applicability conditions of optical evaluation method for bactericidal features of additives.

Int. J. Corros. Scale Inhib., , 2, 112-125 PDF (2 661 K)
doi: 10.17675/2305-6894-2018-7-2-1

Volatile corrosion inhibitors for ferrous and non-ferrous metals and alloys: A review

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1 Department of Applied Chemistry, JETGI, Faculty of Engineering, Barabanki, India-225203
2 Department of Chemistry, School of Mathematical & Physical Sciences, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa
3 Material Science Innovation & Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa
4 Assistant Professor, Department of Civil Engineering, JETGI, Faculty of Engineering, Barabanki, India-225203
5 Center of Research Excellence in Corrosion, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia

Abstract: Volatile corrosion inhibitors (VCIs) or vapor phase inhibitors (VPIs) represent a class of compounds that are employed to protect the corrosion or oxidation of ferrous and non-ferrous metals and alloys where other surface treatments are impractical. The VCIs release slowly inside the sealed airspace and actively adsorb and prevent corrosion. Several VCIs have been employed as effective inhibitors for several metals like iron, zinc, aluminum, etc. and their alloys. Literature study revealed that VCIs protect metallic corrosion either by forming a surface protective film on the metal surface or neutralizing the corrosive surrounding reagents H2O, SO2, H2S and CO2, etc. Because of the high volatility, VCIs easily vaporize and their vapors condense on the metallic surface as well as the volume available in the crevices, pores and cracks thereby gives complete protection where they used. The VCIs can be inserted into coatings, foams, adhesives, powders, sprays and plastics. Several VCIs are known those act as effective inhibitors by themselves and few other VCIs are also known those hydrolyzed products act as corrosion inhibitors. The inhibition ability as well as quantity of the adsorbed VCIs on metallic surfaces can be determined by several commonly employed techniques such as contact angle, radiotracer, polarographic and electrocapilarity methods. Present review article describes the assortment of previous works published on VCIs as corrosion inhibitors for ferrous and non-ferrous metals and alloys. The present report also deals with salient features of VCIs and mechanism of their action.

Int. J. Corros. Scale Inhib., , 2, 126-150 PDF (1 453 K)
doi: 10.17675/2305-6894-2018-7-2-2

Effect of binary mixtures on chloride induced corrosion of rebars in concrete

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Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta” Via Mancinelli 7, 20131 Milano, Italy

Abstract: Rebar corrosion is one of the most important phenomena affecting the durability of reinforced concrete structures. Corrosion inhibitors can be used as a preventative method, able to delay corrosion, or as repair method, to reduce corrosion rate. During more than 15 years in our laboratories an intense experimental research was carried out: the aim of the research was to identify new organic substances or mixtures thereof that might have inhibiting effectiveness. In the paper the effect of binary mixtures on chloride induced corrosion of rebars in concrete is studied; the mixtures are based on two amines, dimethylethanolamine (DMEA) and triethylenetetramine (TETA), and a carboxylate (benzoate); the tests were carried out for comparison purpose also in concrete containing nitrite, acknowledged to be the most effective product. The best results among the binary mixtures were shown by the benzoate–TETA, while the mixtures based on DMEA–TETA were not satisfactory. The performance of the mixtures is not comparable to nitrites.

Int. J. Corros. Scale Inhib., , 2, 151-164 PDF (1 094 K)
doi: 10.17675/2305-6894-2018-7-2-3

A study on the desorption of phosphonic acids, corrosion inhibitor precursors, from polymer microcapsules

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1 A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119071 Russian Federation
2 National Research Moscow State University of Civil Engineering (NRU MGSU), Yaroslavskoye shosse 26, Moscow, 129337 Russian Federation

Abstract: Salts of phosphonic acids are known as efficient corrosion inhibitors in anticorrosive coatings. Incorporation of phosphonates in microscopic capsules into a coating makes it possible to initiate desorption from capsules and diffusion of the inhibitor to the substrate “on demand”. The desorption kinetics of phosphonic acids at the initial stage of contact of a capsule with a water flow and until establishment of a stable inhibitor flux has been studied. The diffusion coefficients of the acid extracted from capsules have been estimated. The efficiency of granulation and extraction processes for building microcapsule walls resistant to water and organic solvents has been shown.

Int. J. Corros. Scale Inhib., , 2, 165-174 PDF (684 K)
doi: 10.17675/2305-6894-2018-7-2-4

Protection of carbon steel against atmospheric corrosion by volatile inhibitors of IFKhAN series at high concentrations of CO2, H2S and NH3

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1 All-Russian Scientific Research Institute of Use of Machinery and Oil Products, Novo-Rubezhnyi per., 28, Tambov, 392022, Russian Federation
2 Tambov State Technical University, ul. Sovetskaya, 106, Tambov, 392000, Russian Federation
3 Derzhavin State University, ul. Internatsyonalnaya, 33, Tambov, 392000, Russian Federation

Abstract: The protective efficacy of volatile inhibitors (VCI) of IFKhAN-A series (A-8, 112, 114, 118) against atmospheric corrosion of carbon steel St3 was studied at room temperature in air in the presence of corrosion stimulants (CS) at specified concentrations: CO2 (0.2–0.6) vol.%, H2S (10–30) mg/m3 and NH3 (20–60) mg/m3. The relative humidity was 100%. Corrosion tests were carried out in sealed containers of 7 liters in volume (desiccators) in two versions. In one version, only one CS was introduced into the air atmosphere. In the other, two or all three used CS were simultaneously injected into the gas phase. To create equilibrium concentrations of the CS in the air atmosphere, a special technique has been developed. The duration of the corrosion tests was 240–528 hours. Potentiodynamic polarization measurements were performed at a potential sweep rate of 0.66 mV/s immediately after immersing the electrodes in the solution and after 24 to 96 hours of their stay in the corrosive medium (in situ). In the presence of CO2 in air atmosphere, the protective efficiency of all the VCIs studied is close to 100%. In the presence of NH3 (20 mg/m3), it is within 74% (IFKhAN-8) to 21% (IFKhAN-118). In the presence of H2S, the protective effect of the VCIs increases again, amounting to 93–97%. In uninhibited systems containing simultaneously two stimulants of corrosion, intense pitting is observed. When CO2 and NH3 are introduced simultaneously, the protective effect of the investigated VCIs is in the range of 76–87%, with CO2+H2S it is 81% (A-112 and 118) to 100% (A-114), and with H2S+NH3, it is 67–85%. The most effective is IFKhAN-114, which not only reduces the corrosion rate, but also eliminates pitting (CO2+NH3). Introduction of IFKhAN-114 allows one to achieve the protective effect of 95% in the presence of all three CS simultaneously. The corrosion rate of steel in the uninhibited background solution is limited by the cathodic reaction. In the presence of (NH4)2S as an NH3 and H2S reaction product, the IFKhAN-114 inhibitor effectively inhibits the anodic process. As a result, the corrosion potential of steel is increased by 0.070 V. The protective effect of IFKhAN-114 obtained from the data of potentiodynamic measurements in this medium immediately after immersing the electrode in the solution, is about 50%. This is lower than the value calculated from the results of gravimetric measurements, due to the different duration of steel aging in the corrosive environment.

Int. J. Corros. Scale Inhib., , 2, 175-184 PDF (515 K)
doi: 10.17675/2305-6894-2018-7-2-5

A comprehensive study of grape pomace extract and its active components as effective vapour phase corrosion inhibitor of mild steel

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1 National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Ave Peremogy 37, Kiev, 03056 Ukraine
2 Ukrainian State Chemical-Engineering University, Gagarin Ave. 8, Dnipro, 49005 Ukraine
3 Chernihiv National T.G. Shevchenko Pedagogical University, 53 Hetmana Polubotka str., 14013 Chernihiv, Ukraine

Abstract: The inhibition efficiency of grape pomace extract (GPE) and its main constituents (2-phenylacetaldehyde, hexanal) as a green volatile corrosion inhibitor for the temporary protection of mild steel was investigated. Weight loss measurements and potentiodynamic polarization techniques were all used for this assessment. The major constituents of GPE were identified by GC-MS analysis. Grape pomace extract inhibited mild steel corrosion under conditions of periodic condensation of moisture with a protection efficiency of ~92%. The gravimetric measurement indicates that inhibition efficiency shows direct proportional relation with concentration of inhibitor. The corrosion rate reduction is time dependent, and the highest protection values were achieved only in 48 h. Inhibition efficiency increases in the order: grape pomace extract > 2-phenylacetaldehyde > hexanal. The grape pomace extract and main components acted as a mixed-type inhibitor with predominant cathodic effectiveness. Structural characterization by using SEM, AFM images and FT-IR analysis further supported the electrochemical and weight loss measurements results obtained.

Int. J. Corros. Scale Inhib., , 2, 185-202 PDF (1 415 K)
doi: 10.17675/2305-6894-2018-7-2-6

Octadecylamine, 1,2,3-benzotriazole and a mixture thereof as chamber inhibitors of steel corrosion

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A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119071 Russian Federation

Abstract: It has been shown that it is possible to create a technology for efficient protection of steel items by short-term treatment in vapors of low-volatile corrosion inhibitors in specialized chambers at elevated temperatures. It is suggested to call this technology based on the protection after-effect of adsorbed inhibitor films as “chamber treatment” and the compounds used therein as “chamber inhibitors”. A number of methods (accelerated and field corrosion tests, potentiodynamic polarization measurements, ellipsometry, surface wetting angle measurement) were used to study the formation of adsorption films of 1,2,3-benzotriazole (BTA), octadecylamine (ODA), and a mixture thereof on steel from a gas phase. It has been found that the temperature plots of the protection after-effect of the inhibitors studied have a maximum at 120°C. The adsorption films that stabilize the passive state of steel (both in the absence of chloride and in chloride-containing electrolytes) and noticeably hydrophobize the surface are already formed within one hour of chamber treatment. The adsorption films of ODA and its mixtures with BTA hinder steel corrosion initiation under conditions of recurrent moisture condensation more than 100-fold and have significantly better protective properties than the adsorption films of BTA. It has been found that adsorption of inhibitors hinders the thermal oxidation of steel. The total thickness of the surface layers on steel (oxide film and adsorbed inhibitor) responsible for the protection after-effect depends on the inhibitor nature but does not exceed 15 nm. It has been shown that treatment in vapors of ODA or its mixture with BTA markedly increases the corrosion resistance of low-carbon steel under weathering conditions and can be used for the interoperational protection of metal items.

Int. J. Corros. Scale Inhib., , 2, 203-212 PDF (653 K)
doi: 10.17675/2305-6894-2018-7-2-7

Inhibitive effect of Artemisia Judaica Herbs extract on the corrosion of carbon steel in hydrochloric acid solutions

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1 Chemistry Department, Faculty of Science, Mansoura University, Mansoura-35516, Egypt
2 Misr Higher Institute for Engineering and Technology, Mansoura, Egypt

Abstract: Artemisia Judaica herb extract (AJH) was tested as an eco-friendly corrosion protection of carbon steel (CS) in 1.0 M hydrochloric acid as attacking medium utilizing non electrochemical methods (mass reduction (MR)), and electrochemical methods such as (EIS) AC electrochemical impedance spectroscopy, and (PP) Tafel polarization tests. The obtained data revealed that the protective efficiency increased with increasing extract dose and also increased with increasing temperature. Surface examination was performed by (AFM) atomic force microscope (in order to determine the degree of roughness of the CS surface), (SEM) scanning electron microscope (in order to determine the film formed on CS surface) and (FT-IR) Fourier transforms infrared spectroscopy (in order to determine the adsorbed groups on CS surface). These tests revealed that the extract molecules form a film on CS surface. The AJH extract was adsorbed physically and spontaneously on CS surface and follows Langmuir's isotherm. The adsorption (Kads, ΔH0ads, ΔG0ads) factors were calculated using adsorption isotherm, and activation (E*a, ΔH*, ΔS*) parameters were determined from Arrhenius and transition state theories and debated. Polarization data revealed that this extract is mixed type one, i.e. affects both anodic metal dissolution and cathodic hydrogen evolution. EIS data revealed that the charge transfer resistance (Rct) increased, on the other hand the capacitance double layer (Cdl) decreased in the presence of AJH extract. Toxicity of the extract was determined by Microtox Model 500 analyzer. Different components in the extract were dedicated by HPLC apparatus. Quantum chemical calculations were performed using Materials Studio 7.0 software and discussed for five main components in the extract.

Int. J. Corros. Scale Inhib., , 2, 213-235 PDF (1 598 K)
doi: 10.17675/2305-6894-2018-7-2-8

Halogen-substituted pyrazolo-pyrimidine derivatives as corrosion inhibitors for copper in sulfuric acid solution

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1 School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
2 School of Material and Chemical Engineering, Tongren University, Tongren 554300, China
3 Chemistry Department, Faculty of Science and Arts, Al Baha University, Baljarashi 65635, Saudi Arabia

Abstract: Sulfuric acid is widely used in several industrial fields, such as acid pickling, acid cleaning and acid descaling, which cause serious corrosion issues. Especially, copper being widely applied in industrial is vulnerable to be corroded by the acid. The usage of corrosion inhibitor is one of the most important techniques for controlling the corrosion. Several organic inhibitors containing hetero-atom, π-electrons and double bond have been applied for the corrosion inhibition of copper, which are found to exhibit high inhibiting properties by providing electrons to interact with metal surface. However, the use of several heterocyclic inhibitors has caused negative impact on the environment due to their toxicity and non-biodegradability. In this paper, pyrazolo-pyrimidine derivatives are found to attract great attention owing to their eco-friendly properties. Corrosion inhibited properties of three pyrazolo-pyrimidine derivatives namely 4-amino pyrazolo-pyrimidine (APP), 3-bromine 4-amino pyrazolo-pyrimidine (Br-APP) and 3-iodine 4-amino pyrazolo-pyrimidine (I-APP) on copper in 0.5 M H2SO4 solution were studied using electrochemical method and surface analysis techniques. Corrosion of copper has been largely inhibited by the inhibitors and the inhibited efficiency increase with the augment of concentration. The adsorption isotherms were simulated to explore the adsorption mode of inhibitors. Furthermore, theoretical calculations were applied to research the mechanism of inhibitors on copper.

Int. J. Corros. Scale Inhib., , 2, 236-249 PDF (1 186 K)
doi: 10.17675/2305-6894-2018-7-2-9

Measurement and calculation of polymeric scale inhibitor concentration in water

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1 Nizhnevartovsk branch of Federal State Budget Educational Institution of Higher Education “Industrial University of Tyumen”, Zapadny promyshlenny yzel, Panel 20, Lenina str. 2/P, bld. 9, Nizhnevartovsk, Tumen oblast, Khanty-Mansi Autonomous Area-Yugra, 628616 Russian Federation
2 Federal state-financed organization of science Institute of Chemistry Far-East department of Russian Academy of Sciences, 100-letya Vladivostoka avenue, 159, 690022 Vladivostok, Russian Federation
3 JSC “Neftegazholding”, Arbatskaya ploshchad, 1, 119019 Moscow, Russian Federation

Abstract: Mineral scale deposition is a well-known problem within the oil and gas industry. Scaling leads to tubing diameter reduction, failure of well equipment, reduction of heater-treaters performance, severe corrosion of tubing and piping internal surface, etc. One of the most widely used methods of scale prevention in oil and gas industry is application of scale inhibitors. A large class of scale inhibitors is presented by reagents with polymers as an active base, the so-called polymeric scale inhibitors. For the successful application of any scale inhibitor, the concentration of applied regents in water phase of an oil production system shall be monitored. However, there is no standard method for analysis of polymeric scale inhibitor concentration in the water phase of oil and gas production systems. Using of energy-dispersive X-ray fluorescence analysis, CHNS-analysis, IR-spectroscopy, pyrolytic chromatography mass spectrometry, low-resolution chromato-mass spectrometry and high performance liquid chromatography, the composition of SCW85370 scale inhibitor (SI) was studied. It was found that scale inhibitor consists of a high molecular sulphated poly acrylic acid. A method for analysis of SCW85370 concentration in water was developed. The lower detection limit of the method does not exceed 3 mg/dm3. Practical results obtained using this method are provided. A formula for calculation of scale inhibitor concentration in formation water produced after scale inhibitor squeeze into formation is proposed. The formula allows the SI concentration to be calculated at any point of time using following data: volume of SI solution squeezed, volume of water squeezed, well water flow rate. It is shown that experimental data is well characterized by the suggested formula.

Int. J. Corros. Scale Inhib., , 2, 250-259 PDF (608 K)
doi: 10.17675/2305-6894-2018-7-2-10

Inhibition of anodic dissolution of Mg90 alloy by adsorption layers of higher carboxylic acids

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A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119071 Russian Federation

Abstract: The passivating ability of thin adsorption films of oleic acid and its sodium salt previously formed on the surface of technical magnesium from ethanolic solutions was studied in borate buffer (pH 9.2) containing aggressive sodium chloride. Analysis of the anodic polarization curves showed that the adsorption protective films formed in an ethanolic solution of oleic acid are more stable than the films of stearic and tridecanoic acids or sodium oleate, which exhibits much more efficient passivating properties upon adsorption from aqueous solutions. Measurements of the wetting contact angle (Θc) on magnesium samples pre-oxidized and treated with ethanolic solutions of carboxylic acids showed that short-term treatment of Mg in oleic acid solution, even with Cin = 16 mM, does not hydrophobize its surface, although it increases the value of the Θc angle in time. However, after immersing the electrode in this solution for 15 hours and then washing it with pure ethanol, the value of Θc is 93 ± 1°, although this value is lower than Θc = 115° measured on the coating formed by the more hydrophobic stearic acid in a much shorter period (10 min). Oleic acid is inferior in the hydrophobizing effect not only to stearic acid but also to the less hydrophobic tridecanoic acid. However, it is possible to enhance the hydrophobization of magnesium surface by formulations of oleic acid with other higher carboxylic acids by means of relatively long treatment in an ethanolic solution.

Int. J. Corros. Scale Inhib., , 2, 260-270 PDF (464 K)
doi: 10.17675/2305-6894-2018-7-2-11

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