Adiponitrile is an
organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...
with the
chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...
(CH
2)
4(CN)
2. This
viscous
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inter ...
, colourless
dinitrile is an important precursor to the
polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...
nylon 66
Nylon 66 (loosely written nylon 6-6, nylon 6/6, nylon 6,6, or nylon 6:6) is a type of polyamide or nylon. It, and nylon 6, are the two most common for textile and plastic industries. Nylon 66 is made of two monomers each containing 6 carbon atoms, ...
. In 2005, about one million tonnes of adiponitrile were produced.
[M. T. Musser, "Adipic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. ]
Production
Early methods
Because of the industrial value of adiponitrile, many methods have been developed for its synthesis. Early industrial methods started from
furfural and later by the
chlorination Chlorination may refer to:
* Chlorination reaction
In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transform ...
of
butadiene
1,3-Butadiene () is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two vi ...
to give 1,4-dichloro-2-butene, which with sodium cyanide, converts to 3-hexenedinitrile, which in turn can be hydrogenated to adiponitrile:
[
:ClCH2CH=CHCH2Cl + 2 NaCN → NCCH2CH=CHCH2CN + 2 NaCl
:NCCH2CH=CHCH2CN + H2 → NC(CH2)4CN
Adiponitrile has also been produced from ]adipic acid
Adipic acid or hexanedioic acid is the organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid: about 2.5 billion kilograms of this white crystalline powder are produced annuall ...
, by dehydration of the diamide, but this is rarely employed.
Modern methods
After patent application in 2004, the majority of adiponitrile is prepared by the nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
-catalysed hydrocyanation
In organic chemistry, hydrocyanation is a process for conversion of alkenes to nitriles. The reaction involves the addition of hydrogen cyanide and requires a catalyst. This conversion is conducted on an industrial scale for the production of ...
of butadiene
1,3-Butadiene () is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two vi ...
, as discovered at DuPont
DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...
, pioneered by Drinkard. The net reaction is:
: CH2=CHCH=CH2 + 2 HCN → NC(CH2)4CN
The process involves several stages, the first of which involves monohydrocyanation (the addition of one molecule of HCN), affording isomers of pentenenitriles as well as 2- and 3-methylbutanenitriles. These unsaturated nitriles are subsequently isomerized to the 3-and 4- pentenenitriles. In the final stage, these pentenenitriles are subjected to a second hydrocyanation, in an anti-Markovnikov sense, to produce adiponitrile.
3-pentenenitrile, formed in the first hydrocyanation, can undergo alkene metathesis
Olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the scission and regeneration of carbon-carbon double bonds. Because of the relative simplicity of olefin metathesis, it often create ...
to give dicyanobutenes, which are readily hydrogenated as described above. A useful byproduct of the production of adiponitrile is 2-methylglutaronitrile.
The other major industrial method involves hydrodimerization Hydrodimerization is an organic reaction that couples two alkenes to give a symmetrical hydrocarbon. The reaction is often implemented electrochemically; in that case the reaction is called electrodimerization. The reaction can also be induced wit ...
, starting from acrylonitrile
Acrylonitrile is an organic compound with the formula and the structure . It is a colorless, volatile liquid although commercial samples can be yellow due to impurities. It has a pungent odor of garlic or onions. In terms of its molecular ...
:
:2 CH2=CHCN + 2 e− + 2 H+ → NCCH2CH2CH2CH2CN
The electrolytic coupling of acrylonitrile was discovered at Monsanto Company.
Applications
Almost all adiponitrile is hydrogenated
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ...
to 1,6-diaminohexane for the production of nylon:
:NC(CH2)4CN + 4 H2 → H2N(CH2)6NH2
Like other nitriles, adiponitrile is susceptible to hydrolysis; however the resulting adipic acid
Adipic acid or hexanedioic acid is the organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid: about 2.5 billion kilograms of this white crystalline powder are produced annuall ...
is less expensively prepared via other routes.
Production
In 2018 there existed approximately 1.5 million tons of capacity. The main producers of adiponitrile are:
*Ascend: Decatur,AL 400kt, being expanded to 580kt by 2022
* Invista: Victoria,TX and Orange,TX.
*Invista and BASF
BASF Societas Europaea, SE () is a German multinational corporation, multinational chemical company and the List of largest chemical producers, largest chemical producer in the world. Its headquarters is located in Ludwigshafen, Germany.
The ...
jv 'Butachimie': Chalampé (France). Production to be increased from 100kt in 2020 to 600kt.
*Asahi Kasei
BASF closed the 128kt ADN plant at Seal Sands in 2009.
In 2015, the Shandong Runxing New Material 100kt plant suffered an explosion and was not reopened.
In 2022, Invista plans to open a 300-400kt plant in Shanghai.
Safety
The for adiponitrile is 300 mg/kg for oral ingestion by rats.[
In 1990, ]ACGIH
The American Conference of Governmental Industrial Hygienists (ACGIH) is a professional association of industrial hygienists and practitioners of related professions, with headquarters in Cincinnati, Ohio. One of its goals is to advance worker p ...
adopted a time-weighted average Threshold Limit Value of 2ppm for work-related skin exposure.
The NIOSH recommended skin exposure limit for a work related time weighted average concentration is 4ppm (18 mg/m3).NIOSH Pocket Guide
NIOSH Publication 2005-149; September 2005
It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act
The Emergency Planning and Community Right-to-Know Act of 1986 is a United States federal law passed by the 99th United States Congress located at Title 42, Chapter 116 of the U.S. Code, concerned with emergency response preparedness.
On October ...
(42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.
References
External links
*
*{{PGCH, 0015
www.chemicalland.com
www.nist.gov
Alkanedinitriles