Acrylonitrile

Acrylonitrile
Names
Preferred IUPAC name
Prop-2-enenitrile
Other names
Acrylonitrile
2-Propenenitrile
Cyanoethene,
Vinylcyanide (VCN)
Cyanoethylene[1]
Propenenitrile[1]
Identifiers
107-13-1 YesY
3D model (Jmol) Interactive image
Interactive image
ChEBI CHEBI:28217 YesY
ChEMBL ChEMBL445612 YesY
ChemSpider 7567 YesY
ECHA InfoCard 100.003.152
EC Number 608-003-00-4
KEGG C01998 YesY
PubChem 7855
RTECS number AT5250000
UNII MP1U0D42PE YesY
UN number 1093
Properties
C3H3N
Molar mass 53.06 g·mol−1
Appearance Colourless liquid
Density 0.81 g/cm3
Melting point −84 °C (−119 °F; 189 K)
Boiling point 77 °C (171 °F; 350 K)
70 g/L
Vapor pressure 83 mmHg[1]
Hazards
Main hazards flammable,
reactive,
toxic,
potential occupational carcinogen[1]
Safety data sheet ICSC 0092
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline) Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazards (white): no codeNFPA 704 four-colored diamond
3
4
2
Flash point −1 °C; 30 °F; 272 K
471 °C (880 °F; 744 K)
Explosive limits 3–17%
Lethal dose or concentration (LD, LC):
500 ppm (rat, 4 hr)
313 ppm (mouse, 4 hr)
425 ppm (rat, 4 hr)[2]
260 ppm (rabbit, 4 hr)
575 ppm (guinea pig, 4 hr)
636 ppm (rat, 4 hr)
452 ppm (human, 1 hr)[2]
US health exposure limits (NIOSH):
PEL (Permissible)
 TWA 2 ppm C 10 ppm [15-minute] [skin][1]
REL (Recommended)
 Ca TWA 1 ppm C 10 ppm [15-minute] [skin][1]
IDLH (Immediate danger)
 85 ppm[1]
Related compounds
Related compounds
 acrylic acid,
acrolein
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Acrylonitrile is an organic compound with the formula CH2CHCN. It is a colorless volatile liquid, although commercial samples can be yellow due to impurities. In terms of its molecular structure, it consists of a vinyl group linked to a nitrile. It is an important monomer for the manufacture of useful plastics such as polyacrylonitrile. It is reactive and toxic at low doses.[3]

Production

Acrylonitrile is produced by catalytic ammoxidation of propylene, also known as the SOHIO process. In 2002, world production capacity was estimated at 5 million tonnes per year.[3][4] Acetonitrile and hydrogen cyanide are significant byproducts that are recovered for sale.[3] In fact, the 2008–2009 acetonitrile shortage was caused by a decrease in demand for acrylonitrile.[5]

2CH3-CH=CH2 + 2NH3 + 3O2 → 2CH2=CH-C≡N + 6H2O

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. Historically, one of the first successful catalysts was bismuth phosphomolybdate supported on silica as a heterogeneous catalyst. Further improvements have since been made.[3]

Historical

Acrylonitrile was first synthesized by the French chemist Charles Moureu (1863–1929) in 1893.[6]

Uses

Acrylonitrile is used principally as a monomer to prepare polyacrylonitrile, a homopolymer, or several important copolymers, such as styrene-acrylonitrile (SAN), acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), and other synthetic rubbers such as acrylonitrile butadiene (NBR). Dimerization of acrylonitrile affords adiponitrile, used in the synthesis of certain polyamides. Small amounts are also used as a fumigant. Acrylonitrile and derivatives, such as 2-chloro-acrylonitrile, are dienophiles in Diels-Alder reactions. Acrylonitrile is also a precursor in the industrial manufacture of acrylamide and acrylic acid.[3]

Health effects

Acrylonitrile is highly flammable and toxic at low doses. It undergoes explosive polymerization. The burning material releases fumes of hydrogen cyanide and oxides of nitrogen. It is classified as a Class 2B carcinogen (possibly carcinogenic) by the International Agency for Research on Cancer (IARC),[7] and workers exposed to high levels of airborne acrylonitrile are diagnosed more frequently with lung cancer than the rest of the population.[8] 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.[9]

Acrylonitrile increases cancer in high dose tests in male and female rats and mice.[10]

Pathways of exposure for humans include emissions, auto exhaust, and cigarette smoke that can expose the human subject directly if they inhale or smoke. Routes of exposure include inhalation, oral, and to a certain extent dermal uptake (tested with volunteer humans and in rat studies).[11] Repeated exposure causes skin sensitization and may cause central nervous system and liver damage.[9]

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 metabolized with 2-cyanoethylene oxide to produce cyanide end products that ultimately forms thiocyanate, which is excreted via urine, or carbon dioxide and eliminated through the lungs.[11] Metabolites can be detected in the blood and urine.[7]

Acrylonitrile induces apoptosis in human umbilical cord mesenchymal stem cells [12]

Environmental effects

Acrylonitrile is harmful to aquatic life.[9]

References

  1. 1 2 3 4 5 6 7 "NIOSH Pocket Guide to Chemical Hazards #0014". National Institute for Occupational Safety and Health (NIOSH).
  2. 1 2 "Acrylonitrile". Immediately Dangerous to Life and Health. National Institute for Occupational Safety and Health (NIOSH).
  3. 1 2 3 4 5 James F. Brazdil (2005), "Acrylonitrile", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a01_177.pub3
  4. ↑ "The Sohio Acrylonitrile Process". American Chemical Society National Historic Chemical Landmarks. Retrieved 2013-05-13.
  5. ↑ A. Tullo. "A Solvent Dries Up". Chemical & Engineering News. 86: 27. doi:10.1021/cen-v086n047.p027.
  6. ↑ See:
  7. 1 2 "Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide". IARC Monographs, Volume 71 (1999)
  8. ↑ Acrylonitrile Fact Sheet (CAS No. 107-13-1). epa.gov
  9. 1 2 3 "CDC - ACRYLONITRILE - International Chemical Safety Cards - NIOSH". www.cdc.gov. Retrieved 2015-07-31.
  10. ↑ "Acrylonitrile: Carcinogenic Potency Database". berkeley.edu.
  11. 1 2 Acrylonitrile Fact Sheet: Support Document (CAS No. 107-13-1). epa.gov
  12. ↑ Sun X (Jan 2014). "Cytotoxic effects of acrylonitrile on human umbilical cord mesenchymal stem cells in vitro.". J Mol Med Rep. 9 (1): 97–102. doi:10.3892/mmr.2013.1802. PMID 24248151.

External links

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