ISSN 2305-6894

2016, Vol. 5, Issue 3 (pp. 190–281)

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Biocorrosion inhibition effect of 2-aminopyrimidine derivatives on SRB

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1 Department of Biotechnology, Science and Arts Faculty, Niğde University, Kampüs, Niğde 51100, Turkey
2 Department of Chemistry, Science Faculty, Ankara University, Tandoğan, Ankara, 06100, Turkey
3 Department of Biology, Science Faculty, Ankara University, Tandoğan, Ankara, 06100, Turkey

Abstract: In the study the biocidal activity and the corrosion inhibitor activity of 2-aminopyrimidines on growth of Desulfotomaculum sp. B2-1 and B2-2 strains and biocorrosion of X65 steel in 63a medium were determined. For this purpose 4 synthetic compounds (2-amino-4-chloro6-methylpyrimidine (AMP1), 2-amino-4-chloro-6-morpholinepyrimidine (AMP3), 2-amino-4-chloro-6-(4-methylpiperazine-1-yl) pyrimidine (AMP8), 2-amino-4-morpholine6-methylpyrimidine (AMP11)) were tested for biocidal activity on Desulfotomaculum sp. Corrosion experiment system were prepared with standard corrosion cell were incubated at 30°C in incubator for bacterial growth. Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization methods were used to identify corrosion with CH Instruments 660B. The AMP1 and AMP3 compounds reduced the growth of Desulfotomaculum sp. at 25 mg/L concentration. Moreover, these synthetic compounds reduced the biocorrosion of X65 steel by B2-1 strain 95% and 91% for AMP1 and AMP3 sequentially.

Int. J. Corros. Scale Inhib., , 3, 273–281 PDF (1 098 K)
doi: 10.17675/2305-6894-2016-5-3-7

N-Substituted amino acids as anticorrosion additives. Part III: N-Acyl amino acids

1 Óbuda University, Faculty of Light Industry and Environmental Engineering, Doberdó u. 6., 1034 Budapest, Hungary
2 Department of Interfaces and Surface Modification, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117 Budapest, Hungary

Abstract: N-Acylated natural amino acids under neutral conditions were in the focus of corrosion experiments. The influence of the α-side chain in the amino acids as well as the alkyl/aryl part of the acyl moiety on the anticorrosion activity was determined by gravimetric test and visualized by atomic force microscopy. The pH-dependence of the inhibitive character allowed the evaluation of the acidic and alkaline conditions on the corrosion inhibition. The analysis of the efficiencies gave information about the importance of the hydrophobic chains either in the amino acid or in the acyl part and of the other functional groups (carboxyl, chloro substituent). On the basis of these numerous efficacy data one can predict in advance the anticorrosion activity of other acylated amino acids.

Int. J. Corros. Scale Inhib., , 3, 263–272 PDF (859 K)
doi: 10.17675/2305-6894-2016-5-3-6

DFT-QSAR studies on corrosion inhibition efficiency of derivatives of thiadiazole, oxadiazole and triazole

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Department of Pure and Applied Chemistry, Faculty of Pure and Applied Sciences, Ladoke Akintola University of Technology, P.M.B 4000, Ogbomoso, Oyo State, Nigeria

Abstract: A class of organic corrosion inhibitors namely; 2,5-bis(4-dimethylaminophenyl)-1,3,4-thiadiazole (DAPT), 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole (DAPO), 3,5-diphenyl-4H-1,2,4-triazole (DHT), 3,5-di(4-pyridyl)-4H-1,2,4-triazole (PHT), 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole (PAOX), 3,5-di(4-methylthiophenyl)-4H-1,2,4-triazole (4- MTHT) were investigated at density functional theory (DFT) B3LYP/6-31G** (d,p) level. The calculated molecular descriptors such as the HOMO, LUMO, the dipole moment, chemical potential (μ), chemical hardness (ղ), softness (s), global nucleophilicity (N) and average Mulliken charges on nitrogen atoms are discussed in relation to the observed inhibitory efficiency for the compounds. The developed qualitative structural activity relationship (QSAR) models relate the calculated molecular descriptors to the corrosion efficiency; thus QSAR model predicted the experimental corrosion efficiencies. The possible sites for nucleophilic and electrophilic attacks on the compounds were analyzed through the Fukui functions.

Int. J. Corros. Scale Inhib., , 3, 248–262 PDF (1 117 K)
doi: 10.17675/2305-6894-2016-5-3-5

Corrosion inhibition properties of Gongronema latifollium extract in acidic media

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1 Electrochemical and Material Science Unit (EMRU), Department of Chemistry, School of Sciences, Federal University of Technology Owerri, Nigeria
2 Department of Chemistry; School of Physical Sciences, Federal University of Technology Owerri, Nigeria

Abstract: Corrosion inhibition of mild steel in 1 M HCl acid solution by Gongronemena latifolium (GL) extract was investigated by weight-loss and electrochemical techniques. A significant decrease in the corrosion rate of mild steel was observed in the presence of the investigated additive and the inhibition efficiency was found to depend on the concentration of the GL extract. The potentiodynamic polarization data indicated that this additive was of mixed type, but the anodic effect was more pronounced. Nyquist plots showed that on increasing the extract concentration, the charge transfer resistance increased and double layer capacitance decreased. Adsorption of inhibitor GL extract on the mild steel surface is found to obey the Langmuir adsorption isotherm. Increase in activation energy of corrosion process in presence of GL extract indicates physical adsorption.

Int. J. Corros. Scale Inhib., , 3, 232–247 PDF (384 K)
doi: 10.17675/2305-6894-2016-5-3-4

Characterization of corrosion products formed on carbon steel in hydrochloric acid medium by 4-(dimethylamino)-1-(6-methoxy6-oxohexyl)pyridinium bromide

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1 Laboratory separation processes, Faculty of Science, Ibn Tofail University, PO Box 242, Kenitra, Morocco
2 Laboratory of Applied Chemistry and Environment, ENSA, Ibn Zohr University, PO Box 1136, 80000 Agadir, Morocco
3 Department of Chemistry, An-Najah National University, P. O. Box 7, Nablus, Palestine
4 Regional Institute for Applied Chemistry Research, IRICA, E-13004, Ciudad Real, Spain
5 Castilla-La Mancha Science and Technology Park, E-02006, Albacete, Spain
6 Bob L. Herd Department of Petroleum Engineering, Texas Tech University, box 43111, Lubbock, Texas

Abstract: The inhibition of corrosion of carbon steel in 1 M HCl by the synthesized ionic liquid 4-(dimethylamino)-1-(6-methoxy-6-oxohexyl)pyridinium bromide (DMOPB) is performed by electrochemical, gravimetric techniques and surface analysis techniques. The efficiency of inhibition increases with the inhibitor concentration and reached 93% at 10-3 M. The polarization data indicate that the tested inhibitor is a mixed type. The adsorption of the inhibitor on the surface of the steel in 1 M HCl follows the adsorption isotherm Langmuir. The study of the effect of temperature (303–333 K) on the behavior of the steel in 1 M HCl in the absence and presence of 10-3 M of the inhibitor shows that the inhibitory efficiencies increase with temperature in this studied range. The corresponding activation parameters in the absence and presence of inhibitor were determined and discussed. The inhibition efficiency was closely related to orbital energies (EHOMO and ELUMO). The correlation between quantum parameters and experimental inhibition efficiency has been validated. Scanning electron microscopy images revealed that the inhibitor formed protective film on mild steel surface.

Int. J. Corros. Scale Inhib., , 3, 209–231 PDF (1 135 K)
doi: 10.17675/2305-6894-2016-5-3-3

Effect of aromatic aldehydes on the electrochemical behavior of bismuth in chloride media

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1 Southern Federal University, Zorge st., 7, Rostov-on-Don, 344090 Russian Federation
2 Don State Technical University, Gagarin square 1, Rostov-on-Don, 344000 Russian Federation

Abstract: The effect of benzaldehyde (I), 2-hydroxy-4-methoxybenzaldehyde (II), 3,4-dimethoxybenzaldehyde (III), and α-bromocinnamaldehyde (IV) on the partial electrode reactions occurring on bismuth in a neutral chloride solution was investigated. It was established that the dependence of cathodic and anodic process rates on aldehyde concentration is not linear. At equal concentrations, I and III better inhibit cathodic hydrogen evolution than compounds II and IV containing more hydrophilic and hydrophobic substituents, respectively. The aldehydes change the basic parameters of the anodic polarization curve of bismuth. It was shown that dissolution of bismuth in chloride solution with and without the aldehydes studied occurs under diffusion control.

Int. J. Corros. Scale Inhib., , 3, 200–208 PDF (271 K)
doi: 10.17675/2305-6894-2016-5-3-2

Biodegradable and renewable raw materials in a new generation of water-treatment products

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Cortec Corporation, 4119 White Bear Parkway, St. Paul, MN 55110, USA

Abstract: Corrosion protection was always the important part of industrial development. Effective corrosion inhibitors prolong the life of equipment and machinery and in this way minimize the use of natural resources including ore, oil, petroleum, water, etc. On the other hand, growing world manufacturing constantly increases the volume of utilized natural resources. A number of regulations were implemented recently for the protection of the environment. The most known among them are North Sea (UK, Norway, Denmark, The Netherlands) and US Gulf Coast lists of the chemicals environmentally acceptable in these regions, limiting the number of chemicals allowed for use in accordance with their level of biodegradability, bioaccumulation and toxicity. This paper presents several products that are very effective in providing corrosion/scale inhibition and also formulated from biodegradable environmentally friendly raw materials, manufactured from renewable resources. Quality of these products is confirmed by laboratory testing according to ASTM and/or other standards and field results.

Int. J. Corros. Scale Inhib., , 3, 190–199 PDF (284 K)
doi: 10.17675/2305-6894-2016-5-3-1

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