Carboxylic acids as corrosion inhibitors for aluminium in acidic and alkaline solutions

1990 ◽  
Vol 37 (3) ◽  
pp. 4-8 ◽  
Author(s):  
M.N. Moussa ◽  
M.M. El‐Tagoury ◽  
A.A. Radi ◽  
S.M. Hassan
Keyword(s):  
Carboxylic Acids ◽  
Corrosion Inhibitors ◽  
Alkaline Solutions

Salts of Sulfated Oleic Acid Amides as Acid Corrosion Inhibitors

2021 ◽  
Vol 625 (3) ◽  
pp. 36-38
Author(s):  
E. K. Aminova ◽  
◽  
V. V. Fomina ◽  
Keyword(s):  
Oleic Acid ◽  
Sulfuric Acid ◽  
Hydrochloric Acid ◽  
Aqueous Solutions ◽  
Carboxylic Acids ◽  
Ammonium Salt ◽  
Dilute Hydrochloric Acid ◽  
Corrosion Inhibitors ◽  
Acid Corrosion ◽  
Protective Ability

This work is a continuation in a series of studies on the preparation of acid corrosion inhibitors based on carboxylic acids. A method of synthesis of acid corrosion inhibitors based on oleic acid amides has been developed. Several syntheses have been carried out to increase its inhibitory properties. The substances were obtained in several stages. At the first stage, amino alcohols were added to the ОA, then the resulting compounds were sulfonated with sulfuric acid. To expand the field of various inhibitors, reactions with bases are produced. As a result, salts of sulfated amides of oleic acid synthesized with amino nitrates, sulfuric acid and aqueous solutions of bases were formed. To establish the effectiveness of the compounds obtained, the protective ability in dilute hydrochloric acid was evaluated. It is established that some of the obtained substances exhibit the corresponding properties of inhibitors. In this case, the most effective is the ammonium salt of sulfated diethanolamide oleic acid.

scholarly journals Formation of carboxylic acids during degradation of monosaccharides

2008 ◽  
Vol 26 (No. 2) ◽  
pp. 113-131 ◽  
Author(s):  
O. Novotný ◽  
K. Cejpek ◽  
J. Velíšek
Keyword(s):  
Free Radicals ◽  
Aqueous Solutions ◽  
Carboxylic Acids ◽  
Sodium Hydroxide Solution ◽  
Model Systems ◽  
Alkaline Solutions ◽  
Hydroxycarboxylic Acids ◽  
Acid Type ◽  
Cannizzaro Reaction ◽  
Benzilic Acid

The formation of low molecular carboxylic and hydroxycarboxylic acids as well as sugar and deoxysugar acids from monosaccharides (D-glucose, D-fructose, D-arabinose, DL-glyceraldehyde, and 1,3-dihydroxyacetone) was studied in three different model systems: aqueous and alkaline solutions of potassium peroxodisulfate (K<sub>2</sub>S<sub>2</sub>O<sub>8</sub>), and sodium hydroxide solution. In total, 3 low molecular carboxylic acids (formic, acetic and propionic), 24 hydroxycarboxylic acids, and 12 corresponding lactones were identified and quantified by GC/MS. Formic, acetic, and propionic acids were isolated by extraction with diethyl ether and directly analysed by GC/MS; hydroxycarboxylic acids and their lactones were monitored as their trimethylsilylated derivatives using the same method. Formic, acetic, L-lactic, glycollic, DL-2,4-dihydroxybutanoic acids and aldonic acids derived from the parent sugars were the most abundant compounds in all model systems. Within the models investigated, the yield of carboxylic acids and hydroxycarboxylic acids (together with their lactones) ranged between 9.3–22.2% (n/n) and between 3.6–116.9% (n/n), respectively. The amount of acids was significantly lower in aqueous solutions of K<sub>2</sub>S<sub>2</sub>O<sub>8</sub> than in the alkaline solutions. The data obtained indicate that lower carboxylic acids are formed by both subsequent reactions (oxidation and/or intramolecular Cannizzaro reaction) of the sugar fragmentation products and direct decomposition of some intermediates such as uloses or hydroperoxides derived from the parent sugars. The acids possessing the original sugar skeleton are formed as a result of sugar oxidation or benzilic acid type rearrangement of deoxyuloses. Lower acids may also be formed by a recombination of free radicals.

Efficiency of Vapor Phase Corrosion Inhibitors for Ferrous Metals in Neutral and Alkaline Solutions

CORROSION ◽  
2011 ◽  
Vol 67 (4) ◽  
pp. 045001-1-045001-7 ◽  
Author(s):  
U. Rammelt ◽  
S. Koehler ◽  
G. Reinhard
Keyword(s):  
Vapor Phase ◽  
Corrosion Inhibitors ◽  
Alkaline Solutions ◽  
Ferrous Metals

Cationic Corrosion Inhibitors for Alkaliborosilicate Glass

1991 ◽  
Vol 257 ◽  
Author(s):  
H.U. Zwicky ◽  
TH. Graber ◽  
R. Grauer ◽  
R. Restani
Keyword(s):  
Dissolution Rate ◽  
Corrosion Inhibitors ◽  
Pure Water ◽  
Reaction Rates ◽  
Alkaline Solutions ◽  
Lead Silicate ◽  
Borosilicate Glasses ◽  
Glass Dissolution ◽  
Inhibiting Effect ◽  
Solid Phases

ABSTRACTThe dissolution behaviour of two alkali borosilicate glasses has been investigated at 90°C in the presence of potential corrosion inhibitors. The added materials were selected on the basis of surface chemistry considerations: Since the dissolution rate of silicate solid phases in alkaline solutions increases with growing negative surface charge, it should be expected that sorbing cations reduce the reaction rates. Due to the formation of insoluble hydroxides and silicates and to the dominance of neutral or negatively charged hydroxo complexes in the pH range of interest, the selection of potential inhibitors is very restricted.The precipitated hydroxides of Al, Zn, Cd and Pb were chosen as the solid phases. Compared with the experiments in pure water, glass dissolution is enhanced in presence of Al(OH)3 and Zn(OH)2. The concentration of the aqua ions is too low for an inhibiting effect. Sorption of silicic acid on the hydroxide accelerates the glass dissolution. Addition of PbO had a strong inhibiting effect in a 28 days experiment. At longer times an insoluble lead silicate is formed and thereby the glass dissolution rate is increased. Cd on the other hand is still effective as an inhibitor after 365 days.Based on the present results, the possibility of using glass corrosion inhibitors in a repository is considered not to be worthwhile.

Carboxylic acids as efficient corrosion inhibitors of aluminium alloys in alkaline media

2018 ◽  
Vol 289 ◽  
pp. 175-192 ◽  
Author(s):  
Joanna Wysocka ◽  
Mateusz Cieslik ◽  
Stefan Krakowiak ◽  
Jacek Ryl
Keyword(s):  
Carboxylic Acids ◽  
Aluminium Alloys ◽  
Corrosion Inhibitors ◽  
Alkaline Media
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