Adipic acid

	Email		Print
	Bookmark		Link

Adipic acid

Adipic acid is the organic compound

Organic compound

An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of compounds such as carbonates, simple oxides of carbon and cyanides, as well as the allotropes of carbon, are considered Inorganic compound....
with the formula

Chemical formula

A chemical formula is a way of expressing information about the atoms that constitute a particular chemical compound, and how the relationship between those atoms changes in chemical reactions....
(CH₂)₄(CO₂H)₂. From the industrial perspective, it is the most important dicarboxylic acid

Carboxylic acid

Carboxylic acids are organic acids characterized by the presence of a carboxyl group, which has the Chemical formula -COH, usually written -COOH or -CO2H....
: About 2.5 billion kilograms of this white crystalline powder are produced annually, mainly as a precursor for the production of nylon

Nylon

Nylon is a generic designation for a family of synthetic polymers known generically as polyamides and first produced on February 28, 1935 by Wallace Carothers at DuPont....
. Adipic acid otherwise rarely occurs in nature.

orically, adipic acid was prepared from various fats using oxidation.

Discussion

Ask a question about 'Adipic acid'

Start a new discussion about 'Adipic acid'

Answer questions from other users

Full Discussion Forum

Preparation

Historically, adipic acid was prepared from various fats using oxidation. Currently adipic acid is produced from a mixture of cyclohexanol

Cyclohexanol

Cyclohexanol is the organic compound with the Chemical formula 5CHOH. The molecule is related to cyclohexane ring by replacement of one hydrogen atom by a hydroxide....
and cyclohexanone

Cyclohexanone

Cyclohexanone is the organic compound with the chemical formula...
called "KA oil", the abbreviation of "ketone-alcohol oil." The KA oil is oxidized with nitric acid

Nitric acid

Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosion and toxic strong acid that can cause severe burns....
to give adipic acid, via a multistep pathway. Early in the reaction the cyclohexanol is converted to the ketone, releasing nitrous acid

Nitrous acid

Nitrous acid is a weak and monobasic acid known only in solution and in the form of nitrite salts.Nitrous acid is used to make diazo from amines; this occurs by nucleophilic attack of the amine onto the nitrite, reprotonation by the surrounding solvent, and double-elimination of water....
:

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

Glutaric acid

Glutaric acid is the organic compound with the chemical formula HO2C3CO2H. Although the related "linear" dicarboxylic acids adipic acid and succinic acids are water-soluble only to a few percent at room temperature, the water-solubility of glutaric acid is over 50%....
and succinic acid

Succinic acid

Succinic acid is a dicarboxylic acid. Succinate plays a biochemical role in the citric acid cycle....
s.

Related processes start from cyclohexanol, which is obtained from the hydrogenation

Hydrogenation

Hydrogenation is the chemical reaction that results from the addition of hydrogen . The process is usually employed to a redox or Saturation organic compounds....
of phenol.

Alternative methods of production

Several methods have been developed by carbonylation

Carbonylation

Carbonylation refers to Chemical_reactions that introduce carbon monoxide into Organic_compound and inorganic compound substrates. Carbon monoxide is abundantly available and conveniently reactive, so it is widely used as a reactant in industrial chemistry....
of butadiene. For example, the hydrocarboxylation proceeds as follows:

CH₂=CHCH=CH₂ + 2 CO + 2 H₂O ? HO₂C(CH₂)₄CO₂H

A method has been reported that utilizes principles of green chemistry

Green chemistry

Green chemistry, also called sustainable chemistry, is a chemical philosophy encouraging the design of products and processes that reduce or eliminate the use and generation of hazardous substances....
in that water is the only by product. Cyclohexene

Cyclohexene

Cyclohexene is a colorless clear liquid cycloalkene with an intense aversive characteristic sharp smell reminiscent of an oil refinery.It is not very stable upon long term storage with exposure to light and air and should be distilled before use to eliminate organic peroxide....
is oxidized with hydrogen peroxide

Hydrogen peroxide

Hydrogen peroxide is a very pale blue liquid which appears colorless in a dilute solution, slightly more viscous than water. It is a weak acid....
using a tungstate

Tungstate

In chemistry a tungstate is a compound that contains an oxoanion of tungsten or is a mixed oxide containing tungsten. The simplest tungstate ion is WO42−, "orthotungstate"....
-based catalyst and a phase transfer catalyst

Phase transfer catalyst

A phase transfer catalyst or PTC in chemistry is a catalyst which facilitates the migration of a reactant in a heterogeneous system from one phase into another phase where reaction can take place....
. The waste product is water.

Uses

By far the majority of the 2.5 billion kg of adipic acid produced annually is used as monomer for the production of nylon

Nylon

Nylon is a generic designation for a family of synthetic polymers known generically as polyamides and first produced on February 28, 1935 by Wallace Carothers at DuPont....
by a polycondensation reaction with hexamethylene diamine forming 6,6-nylon

Nylon

Nylon is a generic designation for a family of synthetic polymers known generically as polyamides and first produced on February 28, 1935 by Wallace Carothers at DuPont....
. Other major applications also involve polymers: it is a monomer for production of Polyurethane

Polyurethane

A polyurethane, commonly abbreviated PU, is any polymer consisting of a chain of organic chemistry units joined by carbamate links. Polyurethane polymers are formed by reacting a monomer containing at least two isocyanate functional groups with another monomer containing at least two alcohol groups in the presence of a catalyst....
and its esters are plasticizer

Plasticizer

Plasticizers or Dispersants are additives that increase the plasticity or fluidity of the material to which they are added, these include plastics, cement, concrete, wallboard and clay bodies....
s, especially in PVC

PVC

Polyvinyl chloride is a plastic.PVC may also refer to:*Param Vir Chakra, India's highest military honor*Peripheral venous catheter*Permanent virtual circuit, a term used in telecommunications and computer networks...
.

In foods

Small but significant amounts of adipic acid are used as a food ingredient as a flavorant and gelling aid.

Safety

Adipic acid, like most carboxylic acids, is a mild skin irritant. It is mildly toxic, with LD50

LD50

In toxicology, the median lethal dose, LD50 , or LCt50 of a toxic substance or radiation is the Dose required to kill half the members of a tested population....
of 3600 mg/kg for oral ingestion by rats.

Appendix

E-number E355.
U.S. FDA citations - GRAS (21 CFR 184.1009), Indirect additive (21 CFR 175.300, 21 CFR 175.320, 21 CFR 176.170, 21 CFR 176.180, 21 CFR 177.1200, 21 CFR 177.1390 , 21 CFR 177.1500, 21 CFR 177.1630 , 21 CFR 177.1680, 21 CFR 177.2420, 21 CFR 177.2600)
European Union Citations - Decision 1999/217/EC - Flavoing Substance; Directive 95/2/EC, Annex IV - Permitted Food Additive; 2002/72/EC, Annex A - Authorized monomer for Food Contact Plastics

Adipic acid

Preparation

Alternative methods of production

Uses

In foods

Safety

Appendix

External links