Carboxylic acid

About: Carboxylic acid is a research topic. Over the lifetime, 48544 publications have been published within this topic receiving 605696 citations.

Kinetics study of esterification of acetic acid with isobutanol in the presence of amberlite catalyst

Abstract: Kinetic data on the esterification of acetic acid with isobutanol have been obtained from both the uncatalyzed and heterogeneously catalyzed reactions using a stirred batch reactor in dioxane. The equilibrium constant, which is independent of temperature ranging from 318 to 368 K, was found to be 4. The uncatalyzed reaction was proved to be second-order reversible. In the presence of the catalyst, on the other hand, the reaction has been found to occur between an adsorbed alcohol molecule and a molecule of acid in the bulk fluid (Eley–Rideal model). It has also been observed that the initial reaction rate decreases with alcohol and water concentrations and it linearly increases with that of acid. The temperature dependency of the constants appearing in the rate expression were also determined.

Hydrophilic Aliphatic Polyesters: Design, Synthesis, and Ring-Opening Polymerization of Functional Cyclic Esters

Abstract: The synthesis and homo- and copolymerization of new cyclic esters containing protected functional groups (hydroxyl, bishydroxyl, amino, and carboxyl) are described. Each of the e-caprolactone derivatives was generated by the Baeyer−Villiger oxidation of the corresponding cyclohexanone derivative. Monoprotection of 1,4-cyclohexanediol by benzylation or esterification was accomplished in moderate yields by reaction of benzyl bromide or 2,2‘-bis(phenyldioxymethyl)propionyl chloride. Each could be oxidized with pyridinium chlorochromate to yield the respective protected hydroxyl and bis(hydroxyl) functional cyclohexanones. The benzyl ether and benzyl ester protecting groups are readily removed by catalytic hydrogenolysis using Pd/C. Alternatively, ethyl-4-ketocyclohexylcarboxylate was hydrolyzed, and the free carboxylic acid was reesterified to the benzyl or tert-butyl 4-ketocyclohexylcarboxylate by esterification with either benzyl bromide or tert-butyl alcohol. These protecting groups were chosen because th...

Epoxidation of Canola Oil with Hydrogen Peroxide Catalyzed by Acidic Ion Exchange Resin

Abstract: Canola oil with an iodine value of 112/100 g, and containing 60% oleic acid and 20% linoleic acid, was epoxidised using a peroxyacid generated in situ from hydrogen peroxide and a carboxylic acid (acetic or formic acid) in the presence of an acidic ion exchange resin (AIER), Amberlite IR 120H. Acetic acid was found to be a better oxygen carrier than formic acid, as it produced about 10% more conversion of ethylenic unsaturation to oxirane than that produced by formic acid under otherwise identical conditions. A detailed process developmental study was then performed with the acetic acid/AIER combination. The parameters optimised were temperature (65 °C), acetic acid to ethylenic unsaturation molar ratio (0.5), hydrogen peroxide to ethylenic unsaturation molar ratio (1.5), and AIER loading (22%). An iodine conversion of 88.4% and a relative conversion to oxirane of 90% were obtained at the optimum reaction conditions. The heterogeneous catalyst, AIER, was found to be reusable and exhibited a negligible loss in activity.

Production Of Peracids Using An Enzyme Having Perhydrolysis Activity

Abstract: A process is provided for producing peroxycarboxylic acids from carboxylic acid esters. More specifically, carboxylic acid esters are reacted with an inorganic peroxide, such as hydrogen peroxide, in the presence of an enzyme catalyst having perhydrolysis activity. The present perhydrolase catalysts are classified as members of the carbohydrate esterase family 7 (CE-7) based on the conserved structural features. Further, disinfectant formulations comprising the peracids produced by the processes described herein are provided.