scholarly journals Etude de l’influence de la basicité sur l’enthalpie de réaction des sels N-méthoxycarbonyl-(oxy)-pyridiniums

2020 ◽  
Vol 14 (4) ◽  
pp. 1489-1498
Author(s):  
Kokou Agbékonyi Agbodan ◽  
Oudjaniyobi Simalou ◽  
Gneiny Whad Tchani ◽  
Koffi Jondo
Keyword(s):  
Corrosion Inhibitors ◽  
Chloride Ion ◽  
Enthalpy Of Reaction ◽  
Salt Formation ◽  
Hammett Constant ◽  
Significant Development ◽  
Stabilizing Agents ◽  
Polar Conjugation ◽  
Réaction Chimique ◽  
Direct Polar Conjugation

Les hétérocycles sont importants, aussi bien dans les domaines biologique, médicinal et thérapeutique (vitamines, hormones, antibiotiques, etc), que dans le secteur industriel et technologique (inhibiteurs de corrosion, colorants, agents stabilisants, pesticides, herbicides. Les chloroformiates ou chlorocarbonates sont les esters dérivés de l’acide chloroformique. La chimie des N-oxydes hétérocycliques (pyridine et N-oxydes) a connu un important développement au cours des dernières années. L’objectif principal du présent travail est l’étude de l’action du métoxycarbonylchloride sur la pyridine et certains de ses dérivés. Après avoir trouvé les conditions optimales, de nouveaux composés à base de pyridine ont été synthétisés. En remplaçant l’ion chlorure par d’autres ions, les produits synthétisés ont été cristallisés avec un bon rendement. La structure des produits a été caractérisée à l’aide de la spectroscopie infra rouge et la résonnance magnétique nucléaire. Spécifiquement, l’influence de la basicité du noyau hétérocyclique sur les enthalpies de formation des sels produits a été étudiée. En conclusion, la réaction chimique de formation est exothermique avec ΔH° < 0 pour tous les sels étudiés. En utilisant les constantes de Hammett sur le noyau de la pyridine, l’étude a monté que ces chaleurs de réaction dépendent de la basicité du noyau hétérocyclique. En perspective on peut envisager une étude de l’influence de la basicité des différents noyaux pyridiniques sur les effets de conjugaison polaire directe sur le groupe azoté dans les sels N-méthoxycarbonyl-(oxy)-pyridiniums.Mots clés: Pyridine N-Oxyde, chloroformiates, synthèse, constante de Hammett.   English Title: Study of the influence of basicity on the enthalpy of reaction of N-methoxycarbonyl- (oxy) -pyridinium salts Heterocycles are important, as well in the biological, medicinal and therapeutic fields (vitamins, hormones, antibiotics, etc.), as in the industrial and technological sector (corrosion inhibitors, dyes, stabilizing agents, pesticides, herbicides). Chloroformates or chlorocarbonates are esters derived from chloroformic acid. The chemistry of heterocyclic N-oxides (pyridine and N-oxides) has experienced significant development in recent years. The main objective of this work is to study the action of metoxycarbonylchloride on pyridine and some of its derivatives. After finding the optimal conditions, new pyridine-based compounds were synthesized. By replacing the chloride ion with other ions, the synthesized products have been crystallized with good yield. Specifically, the influence of the basicity of the heterocyclic nucleus on the enthalpies of salt formation produced has been studied. The enthalpies formation of salt produced have been determined. In conclusion, the chemical reaction of formation is exothermic with ΔH ° < 0 for all the salts studied. Using Hammett's constants on the pyridine nucleus, the study has shown that these reaction heats depend on the basicity of the heterocyclic nucleus. In perspective, we can study the influence of the basicity of the different pyridine rings on the effects of direct polar conjugation on the nitrogen group in the N-methoxycarbonyl- (oxy) -pyridinium salts.Keywords: Pyridine N-Oxide, chloroformates, synthesis, Hammett constant.  

Effect of New Corrosion Inhibitor on Electrochemical Behavior of Prestressed Steel Wire in Simulated Concrete Pore Solution

2014 ◽  
Vol 941-944 ◽  
pp. 1390-1393
Author(s):  
Qi Lei Sun ◽  
Ze Rui Liu ◽  
Yun Zhu Guo ◽  
Feng Liu
Keyword(s):  
Corrosion Inhibitor ◽  
Passive Film ◽  
Corrosion Inhibitors ◽  
Pore Solution ◽  
Steel Wire ◽  
Chloride Ion ◽  
Ammonium Molybdate ◽  
Surface Coat ◽  
Protective Oxide ◽  
Protective Oxide Film

The polarization curve and AC impedance are used to study the impacts of new corrosion inhibitor on the prestressed steel wire electrochemistry action in the simulated concrete pore solution. The result shows that, the ammonium molybdate, DETA, propylene thiourea, 1,4-butynediol and other compound corrosion inhibitors are positive inhibitory corrosion inhibitors, with the components of passivator and healant of protective oxide film, which can contribute to the formation of a passive film of oxide on the rebar surface, repair the defects of rebar surface, coat the entire rebar with a passive film of oxide with good compactness and stability, prevent the chloride ion from penetration, reduce the free rate of iron ions, and thus achieve the anti-corrosion purpose.

Direct polar conjugation in radical copolymerization of styrene with substituted styrenes

1990 ◽  
Vol 32 (6) ◽  
pp. 1242-1246 ◽  
Author(s):  
A.P. Donya ◽  
O.I. Kachurin ◽  
Yu.B. Vysotskii ◽  
V.M. Murav'eva
Keyword(s):  
Radical Copolymerization ◽  
Polar Conjugation ◽  
Direct Polar Conjugation

scholarly journals Control of Chloride Ion Corrosion by MgAlO x /MgAlFeO x in the Process of Chloride Deicing

2021 ◽  
Author(s):  
Dongdong Wang ◽  
Qi Zhu ◽  
Zipeng Xing ◽  
Lei Fang
Keyword(s):  
Corrosion Inhibitor ◽  
Corrosion Inhibitors ◽  
Freezing Point ◽  
Chloride Ion ◽  
Synthesis Temperature ◽  
Molar Ratio ◽  
Dsc Analysis ◽  
Deicing Salt ◽  
Deicing Salts ◽  
Chloride Salts

Abstract The corrosion inhibitor that is added to chloride deicing salt, whose anti-corrosion and low pollution is great significance. LDHs, calcined at high temperature were used as adsorbents to remove various anionic contaminants and it could reduce the solution's freezing point after adsorbing anions. Therefore, this paper reports the use of calcined LDHs as corrosion inhibitors in deicing salts. We analyzed that the removal ability of chloride ion MgAlFeOx was stronger than that of MgAlOx, reaching 85.50%, and the freezing point was lower than that of MgAlOx, the value was -12.0 °C. At the same time, we also found that CaCl2-MgAlOx and CaCl2-MgAlFeOx significantly reduce the corrosion of carbon steel and concrete compared with chloride salts, and CaCl2-MgAlFeOx has the lowest corrosion degree. Hence, we determined that MgAlFeOx was corrosion inhibitor in chloride deicing salt. The metal molar ratio, synthesis temperature and calcination temperature for preparation of MgAl/MgAlFe-LDHs were determined by XRD and TG-DSC analysis that are 9/2/1, 120 ºC and 500 ºC, respectively. The characteristics of MgAlFeOx after Fe3+ addition were studied in detail by Zeta, XRD, XPS, BET and SEM. The mechanism of corrosion inhibitor’s anticorrosion was determined, which was achieved by adsorption and neutralization.

Evaluation and Field Test of Corrosion Inhibitors of Oil Tube Carbon Steel from Shaanbei Oilfield

2020 ◽  
Vol 977 ◽  
pp. 115-120
Author(s):  
Juan Xie ◽  
Xiao Wei Jia ◽  
Hang Juan Huang ◽  
Xiao Jia ◽  
Guang Da Huang ◽  
...  
Keyword(s):  
Corrosion Inhibitors ◽  
Produced Water ◽  
Chloride Ion ◽  
Quality Analysis ◽  
Ion Content ◽  
Water Quality Analysis ◽  
Average Value ◽  
Study Results ◽  
Evaluation Test ◽  
Electrochemical Evaluation

This paper deals with the investigation of the corrosion situation of oil wells on site. On the basis of water quality analysis, the corrosion status of the site was studied on J55 steel used in the field. The most severe water sample was selected as the medium for electrochemical evaluation and on-site. The screening of four corrosion inhibitors was conducted in our study. Results showed that the salinity of the produced water is relatively high (average value of 29819 mg/L), the chloride ion content is high (average value of 17762.8 mg/L), and the corrosion rate is up to 0.1345 mm/a. Scanning electron microscopy (SEM) was used to analyze the corrosion products and morphology of the studied samples. In the electrochemical evaluation test, the TS-001 corrosion inhibitor has a good corrosion inhibition rate, which can reach up to 97.75% when the dosage is 100 mg/L.

Anti-Corrosion Properties of the Reactive Anode and Cathode Inhibitor by Electrochemical Treatment in Aqueous

2013 ◽  
Vol 284-287 ◽  
pp. 31-34
Author(s):  
Han Seung Lee ◽  
Hwa Sung Ryu
Keyword(s):  
Corrosion Inhibitor ◽  
Corrosion Inhibition ◽  
Concrete Structure ◽  
Corrosion Inhibitors ◽  
Chloride Ion ◽  
Passive State ◽  
Molar Ratio ◽  
Ion Content ◽  
Organic Corrosion Inhibitor ◽  
Inhibition Performance

The durability of a concrete structure is most significantly influenced by the corrosion of reinforcing bars, rather than by the deterioration of concrete itself. The corrosion of reinforcement bars due to chloride serves as a main deterioration factor at the interface between the bars and the concrete in the concrete structure. Accordingly, the corrosion inhibitors are widely used to improve the resistance to chloride penetration into reinforced concrete. Corrosion inhibitors are generally divided into the anode-type inorganic inhibitors and anode-cathode-type organic inhibitors, in terms of the reaction type. It is known that when the Cl-:OH- concentration ratio exceeds 0.6%, film on passive state metal on the bar-concrete interface is damaged and local corrosion starts regardless of the chloride ion content. In this study, the performance of the corrosion inhibitor was examined using a potentiostat, with chloride ion contents of 1.2kg/m3 (as reference), 2.4kg/m3, and 4.8kg/m3. The variables were the inhibitor type, Cl-:OH- molar ratio according to the addition of anode-type inorganic corrosion inhibitor (four ratios: 0.0%, 0.3%, 0.6% and 1.2%), and ratio compared to the standard anode-cathode-type organic corrosion inhibitor liquid (four ratios: 0.0, norm 1/2, norm, norm 2 times). As a result, with the anode-type inorganic nitrite corrosion inhibitor, the corrosion inhibition performance was verified with a corrosion potential of -0.30V at a molar ratio of 0.3% or higher when the chloride ion content was 1.2kg/m3, and at a molar ratio of 0.6% or higher when the chloride ion content was 2.4kg/m3 or 4.8kg/m3. With the anode-cathode-type organic corrosion inhibitor, the corrosion inhibition performance was very good at half the standard quantity (0.42kg/m3) regardless of the chloride ion content. From the added corrosion inhibitor quantities, the anode-cathode-type organic corrosion inhibitor had a better corrosion inhibition performance than the anode-type inorganic nitrite corrosion inhibitor.

Seeking to uncover biology's chemical roots

2019 ◽  
Vol 3 (5) ◽  
pp. 435-443 ◽  
Author(s):  
Addy Pross
Keyword(s):  
Environmental Changes ◽  
Biological Systems ◽  
Significant Development ◽  
The Road ◽  
Physical Chemical ◽  
Systems Chemistry ◽  
Biological World ◽  
Inanimate Matter ◽  
The Origin Of Life ◽  
Opening Up

Despite the considerable advances in molecular biology over the past several decades, the nature of the physical–chemical process by which inanimate matter become transformed into simplest life remains elusive. In this review, we describe recent advances in a relatively new area of chemistry, systems chemistry, which attempts to uncover the physical–chemical principles underlying that remarkable transformation. A significant development has been the discovery that within the space of chemical potentiality there exists a largely unexplored kinetic domain which could be termed dynamic kinetic chemistry. Our analysis suggests that all biological systems and associated sub-systems belong to this distinct domain, thereby facilitating the placement of biological systems within a coherent physical/chemical framework. That discovery offers new insights into the origin of life process, as well as opening the door toward the preparation of active materials able to self-heal, adapt to environmental changes, even communicate, mimicking what transpires routinely in the biological world. The road to simplest proto-life appears to be opening up.

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