Adipic acid CAS:124-04-9

Product Name:	Adipic acid
Synonyms:	Adipic acid 124-04-9;adipic acid, butane-1,4-dicarboxylic acid, hexanedioic acid, гександиовая кислота, 1,4-бутандикарбоновая кислота Гександиовая кислота, 1,4-бутандикарбоновая кислота;kyselinaadipova;kyselinaadipova(czech);moltenadipicacid;oxoalcoholadi
CAS:	124-04-9
MF:	C6H10O4
MW:	146.14
EINECS:	204-673-3
Product Categories:	Food additive and acidulant;plasticizer;Industrial/Fine Chemicals;alpha,omega-Alkanedicarboxylic Acids;alpha,omega-Bifunctional Alkanes;Monofunctional & alpha,omega-Bifunctional Alkanes
Mol File:	124-04-9.mol

density:	1,36 g/cm3
Melting point:	151-154 °C(lit.)
Boiling point:	265 °C100 mm Hg(lit.)
form:	Solid
storage temp.:	Store below +30°C.
Water Solubility:	1.44 g/100 mL (15 ºC)
pka:	4.43(at 25℃)
BRN:	1209788
InChIKey:	WNLRTRBMVRJNCN-UHFFFAOYSA-N
Fp:	385 °F
solubility:	methanol: 0.1 g/mL, clear, colorless
NIST Chemistry Reference:	Hexanedioic acid(124-04-9)
Merck:	14,162
Stability:	Stable. Substances to be avoided include ammonia, strong oxidizing agents.
vapor pressure:	1 mm Hg ( 159.5 °C)
vapor density:	5 (vs air)
FEMA:	2011 \| ADIPIC ACID
JECFA Number:	623
CAS DataBase Reference:	124-04-9(CAS DataBase Reference)
EPA Substance Registry System:	Adipic acid (124-04-9)

Index Name	Specification	Result
Appearance	White Crystal Powder	White Crystal Powder
Purity% (m / m) ≥	99.80	99.81
Melting point dc≥	152.0	152.8
Moisture % (m / m) ≤	0.20	0.19
Ammonia Solution Colour(PT-CO) ≤	5	0.7
Fe mg / kg ≤	0.4	0.1
HNO3 mg/kg≤	3.0	0.86
Ashes mg / kg ≤	4	1.0

Adipic acid Usage And Synthesis

Description	Adipic acid is a crystalline powder with practically no odor. It has the lowest acidity of any of the acids commonly used in foods and has excellent buffering capacity in the range of pH 2.5 to 3.0. Like succinic and fumaric acid, adipic acid is practically nonhygroscopic. Its addition to foods imparts a smooth, tart taste. In grape-flavored products, it adds a lingering supplementary flavor and gives an excellent set to food powders containing gelatin. As a result, adipic acid has found a wide number of uses as an accidulant in dry powdered food mixtures, especially in those products having delicate flavors and where addition of tang to the flavor is undesirable. Its aqueous solutions have the lowest acidity of any of the common food acids. For concentrations from 0.5 to 2.4 g/100 mL, the pH of its solution varies less than half a unit. Hence, it can be used as a buffering agent to maintain acidities within the range of 2.5 to 3.0. This is highly desirable in certain foods, yet the pH is low enough to inhibit the browning of most fruits and other foodstuffs.
Chemical Properties	Adipic acid is the organic compound with the formula (CH₂)₄(COOH)₂. From the industrial perspective, it is the most important dicarboxylic acid: About 2.5 billion kilograms of this white crystalline powder are produced annually, mainly as a precursor for the production of nylon. Adipic acid otherwise rarely occurs in nature.
Physical properties	Adipic acid is a straight-chain dicarboxylic acid that exists as a white crystalline compound at standard temperature and pressure. Adipic acid is one of the most important industrial chemicals and typically ranks in the top 10 in terms of volume used annually by the chemical industry.
Occurrence	Reported found as a minor constituent in butter, and has been found in other fats as a product of oxidative rancidity. It also occurs in beet juice, pork fat, guava fruit (Psidium guajava L.), papaya (Carica papaya L.) and raspberry (Rubus idaeus L.).
Uses	Adipic acid’s main use is in the production of 6,6 nylon. It is also used in resins, plasticizers, lubricants, polyurethanes, and food additives.
Uses	Adipic Acid is primarily used in the synthesis of nylon. It has been used as a reagent in the solid-state polymerization of nylon analogs.
Uses	Adipic Acid is an acidulant and flavoring agent. it is characterized as stable, nonhygroscopic, and slightly soluble, with a water solubility of 1.9 g/100 ml at 20°c. it has a ph of 2.86 at 0.6% usage level at 25°c. it is used in powdered drinks, beverages, gelatin desserts, loz- enges, and canned vegetables. it is also used as a leavening acidulant in baking powder. it can be used as a buffering agent to maintain acidities within a range of ph 2.5–3.0. it is occasionally used in edi- ble oils to prevent rancidity.
Production Methods	Adipic acid is prepared by nitric acid oxidation of cyclohexanol or cyclohexanone or a mixture of the two compounds. Recently, oxidation of cyclohexene with 30% aqueous hydrogen peroxide under organic solvent- and halide-free conditions has been proposed as an environmentally friendly alternative for obtaining colorless crystalline adipic acid.
Definition	ChEBI: An alpha,omega-dicarboxylic acid that is the 1,4-dicarboxy derivative of butane.
Production Methods	Adipic acid can be manufactured using several methods, but the traditional and main route of preparation is by the two-step oxidation of cyclohexane (C₆H₁₂). In the first step, cyclohexane is oxidized to cyclohexanone and cyclohexanol with oxygen or air. This occurs at a temperature of approximately 150°C in the presence of cobalt or manganese catalysts. The second oxidation is done with nitric acid and air using copper or vanadium catalysts. In this step, the ring structure is opened and adipic acid and nitrous oxide are formed. Other feedstocks such as benzene and phenol may be use to synthesize adipic acid. Adipic acid production used to be a large emitter of nitrous oxide, a greenhouse gas, but these have been controlled in recent years using pollution abatement technology.
Preparation	Adipic acid is produced from a mixture of cyclohexanol and cyclohexanone called "KA oil", the abbreviation of "ketone-alcohol oil." The KA oil is oxidized with nitric acid to give adipic acid, via a multistep pathway. Early in the reaction the cyclohexanol is converted to the ketone, releasing nitrous acid: HOC₆H₁₁ + HNO₃ → OC₆H₁₀ + HNO₂ + H₂O Among its many reactions, the cyclohexanone is nitrosated, setting the stage for the scission of the C- C bond: HNO₂ + HNO₃ → NO+NO₃^-+ H₂O OC₆H₁₀ + NO⁺→ OC₆H₉^-2 - NO + H⁺ Side products of the method include glutaric and succinic acids. Related processes start from cyclohexanol, which is obtained from the hydrogenation of phenol.
Reactions	Adipic acid is a dibasic acid (can be deprotonated twice). Its pKa's are 4.41 and 5.41. With the carboxylate groups separated by four methylene groups, adipic acid is suited for intramolecular condensation reactions. Upon treatment with barium hydroxide at elevated temperatures, it undergoes ketonization to give cyclopentanone.
Health Hazard	Exposures to adipic acid cause pain, redness of the skin and eyes, tearing or lacrimation. Adipic acid has been reported as a non-toxic chemical. Excessive concentrations of adipic acid dust are known to cause moderate eye irritation, irritation to the skin, and dermatitis.It may be harmful if swallowed or inhaled. It causes respiratory tract irritation with symptoms of coughing, sneezing, and blood-tinged mucous.
Pharmaceutical Applications	Adipic acid is used as an acidifying and buffering agent in intramuscular, intravenous and vaginal formulations. It is also used in food products as a leavening, pH-controlling, or flavoring agent. Adipic acid has been incorporated into controlled-release formulation matrix tablets to obtain pH-independent release for both weakly basicand weakly acidic drugs.It has also been incorporated into the polymeric coating of hydrophilic monolithic systems to modulate the intragel pH, resulting in zero-order release of a hydrophilic drug.The disintegration at intestinal pH of the enteric polymer shellac has been reported to improve when adipic acid was used as a pore-forming agent without affecting release in the acidic media.Other controlled-release formulations have included adipic acid with the intention of obtaining a late-burst release profile.
Safety Profile	Poison by intraperitoneal route. Moderately toxic by other routes. A severe eye irritant. Combustible when exposed to heat or flame; can react with oxidzing materials. When heated to decomposition it emits acrid smoke and fumes.
Safety	Adipic acid is used in pharmaceutical formulations and food products. The pure form of adipic acid is toxic by the IP route, and moderately toxic by other routes. It is a severe eye irritant, and may cause occupational asthma. LD₅₀ (mouse, IP): 0.28 g/kg LD₅₀ (mouse, IV): 0.68 g/kg LD₅₀ (mouse, oral): 1.9 g/kg LD₅₀ (rat, IP): 0.28 g/kg LD₅₀ (rat, oral): >11 g/kg
Chemical Synthesis	By oxidation of cyclohexanol with concentrated nitric acid; by catalytic oxidation of cyclohexanone with air.
Potential Exposure	Workers in manufacture of nylon, plasticizers, urethanes, adhesives, and food additives
storage	Adipic acid is normally stable but decomposes above boiling point. It should be stored in a tightly closed container in a cool, dry place, and should be kept away from heat, sparks, and open flame.
Shipping	UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required
Purification Methods	For use as a volumetric standard, adipic acid is crystallised once from hot water with the addition of a little animal charcoal, dried at 120o for 2hours, then recrystallised from acetone and again dried at 120o for 2hours. Other purification procedures include crystallisation from ethyl acetate and from acetone/petroleum ether, fusion followed by filtration and crystallisation from the melt, and preliminary distillation under vacuum. [Beilstein 2 IV 1956.]
Incompatibilities	Adipic acid is incompatible with strong oxidizing agents as well as strong bases and reducing agents. Contact with alcohols, glycols, aldehydes, epoxides, or other polymerizing compounds can result in violent reactions.
Waste Disposal	Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed
Precautions	Occupational workers should avoid contact of the adipic acid with the eyes, avoid breathing dust, and keep the container closed. Workers should use adipic acid only with adequate ventilation. Workers should wash thoroughly after handling adipic acid and keep away from heat, sparks, and flame. Also, workers should use rubber gloves and laboratory coats, aprons, or coveralls, and avoid creating a dust cloud when handling, transferring, and cleaning up.
Regulatory Status	GRAS listed. Included in the FDA Inactive Ingredients Database (IM, IV, and vaginal preparations). Accepted for use as a food additive in Europe. Included in an oral pastille formulation available in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.