Fatty acids are the primary natural starting materials for the production of surfactant and detergent molecules. Derived from vegetable (oil) and animal (fat) triglyceride sources, the fatty acids are linear aliphatic carboxylic acids. Industrial interest in branched-chain fatty acids is driven by the needs for products with enhanced performance benefits including higher solubility, ease of handling, better hard water tolerance, and improved oxidative stability. Therefore, catalytic processes have been developed for the conversion of linear fatty acids to branched ones. High yields of branched acids are obtained from unsaturated fatty acids over acidic zeolites, particularly those with large pores. Fatty esters also are readily isomerized to branched ones by means of the same catalyst and process. It is postulated that the isomerization of fatty acids proceeds through three-and four-membered ring carbocation intermediates formed inside the largepore zeolites. This is supported by evidence of methyl and ethyl branching in the primary and final products. The total number of carbon atoms in the fatty acid molecule is unchanged. Surfactants derived from branched fatty acids show favorable physical properties, including a lower viscosity and improved handling, even as intended performance characteristics are maintained. Abbreviations: BFA, branched fatty acid; HIO, hydrogenated isomerized oleic acid; HO, hydrogenated oleic acid; IV, iodine value.
There are a considerable number of stable crystalline salts of the ammonium ion, \documentclass{article}\pagestyle{empty}\begin{document}${{\rm{NH}}^{+}_{4}}$\end{document} . Several are of commercial importance because of large‐scale consumption in fertilizer and industrial markets. These salts are often isomorphous and have similar solubility in water. Compounds in which the ammonium ion is combined with a large, uninegative anion are usually the most stable. Ammonium salts containing a small, highly charged anion generally dissociate easily into ammonia and the free acid. Both normal or neutral ammonium acetate, NH 4 C 2 H 3 O 2 , and the acid salt are known. Ammonium bicarbonate is easily formed. It is produced as both food and standard grade. Normal ammonium carbonate, a crystalline solid, is the principal ingredient of smelling salts because of its characteristic strong ammonia odor. Diammonium citrate is made by neutralization of citric acid. The crystalline or granular product is used as a chemical reagent and as a diuretic. Ammonium chloride, ammonium bromide, and ammonium iodide are crystalline, ionic compounds that exhibit high vapor pressures at elevated temperatures and sublime readily. Aqueous solutions of ammonium halides are acidic. A process based on metathesis or double decomposition is generally preferred for manufacture of ammonium chloride. Several commercial grades are available. Ammonium chloride is used as a nitrogen source for fertilization of rice, wheat, and other crops. Ammonium chloride serves as an electrolyte in the manufacture of drycell batteries, is also used to make quarrying explosives. Ammonium bromide and iodide are manufactured either by the reaction of ammonia with the corresponding hydrohalic acid or by the reaction of ammonia with elemental bromine or iodine. Ammonium bromide is used to manufacture chemical intermediates, and in photographic chemicals. There are two fluoride salts of ammonia: ammonium fluoride, principally a laboratory reagent, and ammonium bifluoride, used primarily as a less hazardous substitute for hydrofluoric acid. In addition to frosting glass, uses of the bifluoride include removing scale from boiler tubes and defouling oil wells. Properties, manufacture, and applications are described. Ammonium nitrate, a white, crystalline salt that is highly soluble in water, is the most commercially important ammonium compound both in terms of production volume and usage. It is the principal component of most industrial explosives and nonmilitary blasting compositions; however, it is used primarily as a nitrogen fertilizer. Ammonium nitrate is considered a very stable salt, but when heated to temperatures from 200 to 230°C, exothermic decomposition occurs. The reaction is rapid, but can be controlled. Above 230°C, exothermic elimination of N 2 and NO 2 begin, and a final violent exothermic reaction occurs with great rapidity when ammonium nitrate detonates. When used in blasting, ammonium nitrate is mixed with fuel oil and sometimes sensitizers such as powdered aluminum. Modern commercial processes for ammonium nitrate rely almost exclusively on the neutralization of nitric acid with ammonia. Ammonium nitrate can be considered a safety material if treated and handled properly. Potential hazards include those associated with fire, decomposition accompanied by generation of toxic fumes, and explosion. Many plants outside of North America prill or granulate a mixture of ammonium nitrate and calcium carbonate. Production of this mixture, often called calcium ammonium nitrate, essentially removes any explosion hazard. Ammonium sulfate, a white, soluble, crystalline salt, is produced from the direct neutralization of sulfuric acid with ammonia. Used as a fertilizer, it is valued both for its nitrogen content and for its readily available sulfur content. Ammonium sulfide and ammonium hydrosulfide are used by the textile industry. Most quaternary ammonium compounds produced in the United States are formulated into consumer products. The largest markets for quaternaries are fabric softening, hair care, bactericidal and germicidal applications, and for manufacture of organoclays. When one of the alkyl groups contains ∼ 10 carbon atoms, the molecules exhibit surface‐active properties. Physical properties are determined by the chemical structure of the material. Reactions include eliminations, displacements, and rearrangements. There are also many biologically important quaternaries. Most quaternaries are biodegradable. Quaternaries are prepared by the reaction of a tertiary amine with an alkylating agent. Commercial production from natural fats and oils, α‐olefins, and fatty alcohols is described. Quaternized esteramines are gaining market share in Western Europe. Other classes of quaternaries include phase‐transfer catalysts, polyamine‐based quaternaries, and perfluorinated quaternaries.
Reaction of benzamides and N-substituted benzamides with appropriate o-alkenyl and -alkynyl side-chains and (chlorocarbony1)phenyl ketene gives transient anhydro-I ,3-oxazinium hydroxides which readily undergo intramolecular 1,4-dipolar cycloaddition; loss of C 0 2 from these 1 : 1 -cycloadducts, isolable with N-su bstituted systems and alkenyl side-chains, gives chromeno[4,3-b]pyridin-2-ones.Intramolecular 1,3-dipolar cycloadditions have become an established method for heterocycle construction;' intramolecular 1 ,bdipolar cycloadditions have received less attention , with difficulties encountered in generating the 174-dipole being avoided by incorporating the 1,4-dipole in a heterocyclic betaine.2 We now describe an approach in which the heteroaromatic betaine is generated in situ and the use of tautomerism in this is exploited.t Author to whom enquiries about X-ray crystallographic analysis shoud be directed.
Most quaternary ammonium compounds produced in the United States are formulated into consumer products. The largest markets for quaternaries are fabric softening, hair care, bactericidal and germicidal applications, and for manufacture of organoclays. When one of the alkyl groups contains around 10 carbon atoms, the molecules exhibit surface‐active properties. Physical properties are determined by the chemical structure of the material. Reactions include eliminations, displacements, and rearrangements. There are also many biologically important quaternaries. Most quaternaries are biodegradable. Quaternaries are prepared by the reaction of a tertiary amine with an alkylating agent. Commercial production from natural fats and oils, α‐olefins, and fatty alcohols is described. Quaternized esteramines are gaining market share in Western Europe. Other classes of quaternaries include phase‐transfer catalysts, polyamine‐based quaternaries, and perfluorinated quaternaries.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.