Isobutanol

Isobutanol
IUPAC name	2-Methylpropan-1-ol
Other names	Isobutyl alcohol, IBA, 2-Methylpropyl alcohol
Identifiers
InChI	InChI=1/C4H10O/c1-4(2)3-5/h4-5H,3H2,1-2H3
InChIKey	ZXEKIIBDNHEJCQ-UHFFFAOYAQ
Standard InChI	InChI=1S/C4H10O/c1-4(2)3-5/h4-5H,3H2,1-2H3
Standard InChIKey	ZXEKIIBDNHEJCQ-UHFFFAOYSA-N
CAS number	[78-83-1]
EC number	201-148-0
RTECS	NP9625000
ChemSpider	6312
SMILES	CC(C)CO
Properties
Chemical formula	C4H10O
Molar mass	74.122 g/mol
Appearance	colorless liquid
Density	0.802 g/cm3, liquid
Melting point	-108 °C (165 K)
Boiling point	108 °C (381 K)
Solubility in water	limited solubility
log P	0.8
Refractive index (nD)	1.3959
Viscosity	3.95 cP at 20 ºC
Hazards
Material safety data sheet (MSDS)	ICSC 0113
EU index number	603-108-00-1
GHS pictograms
GHS signal word	DANGER
GHS hazard statements	H226, H335, H315, H318, H336
Flash point	28 °C (82 ºF)
Autoignition temp.	415 ºC (779 ºF)
Explosive limits	1.7–10.9%
PEL (U.S.)	100 ppm TWA
IDLH level	1600 ppm
Related compounds
Other butanols	Butan-1-ol Butan-2-ol 2-Methylpropan-2-ol
Other compounds	Isobutyraldehyde Isobutyric acid
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol; also known as 2-methylpropyl alcohol, among other names) is a colorless, flammable, organic compound with a characteristic smell. Its isomers are n-butanol, 2-butanol, and tert-butanol. It is classified as an alcohol, and, as such, it is widely used as a solvent in chemical reactions, as well as being a useful starting material for organic synthesis.

Isobutanol is produced naturally during the fermentation of carbohydrates. It may also be a by-product of the decay process of organic matter.

Applications

• feedstock in the manufacture of isobutyl acetate, which is used in the production of lacquer and similar coatings, and in the food industry as a flavouring agent
• in the industrial synthesis of derivative esters; isobutyl esters such as diisobutyl phthalate (DIBP) are used as plasticizer agents in plastics, rubbers, and other dispersions
• as paint solvent
• as varnish remover
• as ink
• as paint additive, to reduce viscosity
• as paint additive, to improve brush flow
• as paint additive, to retard the formation of oil residues (blush) on painted surfaces
• as gasoline additive, to reduce carburetor icing
• as additive to automotive polish
• as additive to automotive paint cleaner
• as a chemical extractant in production of organic compounds
• as a mobile phase in thin layer chromatography.

Isobutanol could possibly serve as an alternative to gasoline to fuel combustion engines, and it is being studied by companies such as Gevo for this use.

Safety

Isobutanol is a volatile, flammable liquid that should be stored and used in well-ventilated areas. It is moderately irritating to the skin and greatly irritating to the eyes, mucous membranes, and respiratory tract. Exposure to high concentrations of its vapour can cause temporary narcosis.

Isobutanol is considered to be slightly toxic and it has been shown to cause liver damage in mice and humans. Ingestion may also lead to alcohol poisoning.

In March 2009 the Canadian government announced its ban of isobutanol in cosmetics.

Further reading

• Pentland, William Beyond Ethanol, <http://www.forbes.com/2008/03/19/innovation-ethanol-fuel-tech-innovation08-cx_wp_0319innovation.html> (accessed 31 August 2009), Forbes; .

External links

• International Chemical Safety Card 0113
• NIOSH Pocket Guide to Chemical Hazards 0352
• IPCS Environmental Health Criteria 65: Butanols: four isomers
• IPCS Health and Safety Guide 9: Isobutanol