Acrylonitrile is an organic compound with the Chemical formula and the structure . It is a colorless, volatile liquid. It has a pungent odor of garlic or onions.[
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Acrylonitrile is one of the components of ABS plastic (acrylonitrile butadiene styrene).
Structure and basic properties
Acrylonitrile is an organic compound with the Chemical 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.[
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Production
Acrylonitrile was first synthesized by the French chemist Charles Moureu in 1893.[
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See especially pp. 187–189 ("Nitrile acrylique ou cyanure de vinyle (Propène-nitrile)").
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Acrylonitrile is produced by catalyst ammoxidation of propylene, also known as the SOHIO process. In 2002, world production capacity was estimated at 5 million tonnes per year,[ In fact, the 2008–2009 acetonitrile shortage was caused by a decrease in demand for acrylonitrile.]
In the SOHIO process, propylene, ammonia, and air (oxidizer) are passed through a fluidized bed reactor containing the catalyst at 400–510 °C and 50–200 kPag. The reactants pass through the reactor only once, before being quenched in aqueous sulfuric acid. Excess propylene, carbon monoxide, carbon dioxide, and dinitrogen that do not dissolve are vented directly to the atmosphere, or are incinerated. The aqueous solution consists of acrylonitrile, acetonitrile, hydrocyanic acid, and ammonium sulfate (from excess ammonia). A recovery column removes bulk water, and acrylonitrile and acetonitrile are separated by distillation. One of the first useful catalysts was bismuth phosphomolybdate () catalyst support on silica.[
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Alternative routes
Various green chemistry routes to acrylonitrile are being explored from renewable feedstocks, such as lignocellulosic biomass, glycerol (from biodiesel production), or glutamic acid (which can itself be produced from renewable feedstocks). The lignocellulosic route involves fermentation of the biomass to propionic acid and 3-hydroxypropionic acid, which are then converted to acrylonitrile by dehydration and ammoxidation.
Uses
Acrylonitrile is used principally as a monomer to prepare polyacrylonitrile, a homopolymer, or several important , such as styrene-acrylonitrile (SAN), acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), and other such as Nitrile rubber (NBR). Hydrodimerization of acrylonitrile
Acrylonitrile is also a precursor in the manufacture of acrylamide and acrylic acid.[
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Synthesis of chemicals
Hydrogenation of acrylonitrile is one route to propionitrile. Hydrolysis with sulfuric acid gives acrylamide sulfate, . This salt can be converted to acrylamide with treatment with base or to methyl acrylate by treatment with methanol.[
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The reaction of acrylonitrile with protic nucleophiles is a common route to a variety of specialty chemicals. The process is called cyanoethylation:
Typical protic nucleophiles are alcohols, , and especially .
Acrylonitrile and derivatives, such as 2-chloroacrylonitrile, are in Diels–Alder reactions.
Health effects
Acrylonitrile is toxic with LD50 = 81 mg/kg (rats). It undergoes explosive polymerization. The burning material releases fumes of hydrogen cyanide and nitrogen dioxide. It is classified as a Class 1 carcinogen (carcinogenic) by the International Agency for Research on Cancer (IARC),[ Acrylonitrile Fact Sheet (CAS No. 107-13-1). epa.gov] Acrylonitrile is one of seven in cigarette smoke that are most associated with respiratory tract carcinogenesis.[ "Acrylonitrile: Carcinogenic Potency Database".] and induces apoptosis in human umbilical cord mesenchymal stem cells.
It evaporates quickly at room temperature (20 °C) to reach dangerous concentrations; skin irritation, respiratory irritation, and eye irritation are the immediate effects of this exposure.[ Acrylonitrile Fact Sheet: Support Document (CAS No. 107-13-1). epa.gov] Repeated exposure causes skin sensitization and may cause central nervous system and liver damage.
There are two main excretion processes of acrylonitrile. The primary method is excretion in urine when acrylonitrile is metabolized by being directly conjugated to glutathione. The other method is when acrylonitrile is enzymatically converted into 2-cyanoethylene oxide which will produce cyanide end products that ultimately form thiocyanate, which is excreted via urine.
In July 2024, the International Agency for Research on Cancer upgraded acrylonitrile's classification from 'possibly carcinogenic' to Carcinogen for humans. The Agency found sufficient evidence linking it to lung cancer.
Use in plastic bottles
In June 1974 Coca-Cola introduced the acrylonitrile/styrene 32oz Easy‐Goer plastic bottle, offering energy savings during manufacture, increased durability, and weight savings over glass.
Incidents
A large amount of acrylonitrile (approximately 6500 tons) leaked from an industrial polymer plant owned by Aksa Akrilik after the violent 17th August 1999 earthquake in Turkey. Over 5000 people were affected and the exposed animals had died.[ Aksa Akrilik was sued by 200 residents who were affected by acrylonitrile.][ as the cancer rate in the affected area has increased by 80%, from 1999 to April 2002.][ In 2003, the owner of Aksa Akrilik died from lung cancer related to acrylonitrile exposure.][ As of 2001, this is the largest known acrylonitrile leak.][
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Occurrence
Acrylonitrile is not naturally formed on Earth. It has been detected at the sub-ppm level at industrial sites. It persists in the air for up to a week. It decomposes by reacting with oxygen and hydroxyl radical to form formyl cyanide and formaldehyde.
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