Isobutanol

Isobutanol
IUPAC name	2-Methylpropan-1-ol
Other names	Isobutyl alcohol, IBA, 2-methylpropyl alcohol
Identifiers
CAS number	78-83-1 Y
EC-number	201-148-0
RTECS number	NP9625000
SMILES	CC(C)CO
InChI	1/C4H10O/c1-4(2)3-5/h4-5H,3H2,1-2H3
ChemSpider ID	6312
Properties[1]
Molecular 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[1]
MSDS	ICSC 0113
EU Index	603-108-00-1
EU classification	Irritant (Xi)
R-phrases	R10, R37/38, R41, R67
S-phrases	(S2), S7/9, S13, S26, S37/39, S46
NFPA 704	3 1 0
Flash point	28 °C (82 ºF)
Autoignition temperature	415 ºC (779 ºF)
Explosive limits	1.7–10.9%
Related compounds
Related butanols	n-Butanol sec-Butanol tert-Butanol
Related compounds	Isobutyraldehyde Isobutyric acid
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol) is an organic compound with the formula (CH₃)₂CHCH₂OH. This colorless, flammable liquid with a characteristic smell is mainly used as a solvent. Its isomers include n-butanol, 2-butanol, and tert-butanol, all of which are more important industrially.

Production

Isobutanol is produced by the carbonylation of propylene. Two methods are practiced industrially, hydroformylation is more common and generates a mixture of normal and isobutyraldehydes, which are hydrogenated to the alcohols and then separated. Reppe carbonylation is also practiced.^[2]

Isobutanol is produced naturally during the fermentation of carbohydrates. It may also be a by-product of the decay process of organic matter.^{[citation needed]}

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
• precursor of derivative esters; isobutyl esters such as diisobutyl phthalate (DIBP) are used as plasticizer agents in plastics, rubbers, and other dispersions
• paint solvent
• varnish remover
• ink
• paint additive, to reduce viscosity, improve brush flow, and retard formation of oil residues (blush) on painted surfaces
• gasoline additive, to reduce carburetor icing
• automotive polish additive
• automotive paint cleaner additive
• chemical extractant in production of organic compounds
• mobile phase in thin layer chromatography.

Isobutanol could possibly serve as an alternative to gasoline to fuel combustion engines, and it is being produced by companies such as Gevo for this use in a joint venture with Cargill.^[3] A 1993 SAE technical paper addresses blending methanol, ethanol and isobutanol with unleaded gasoline for use as a motor fuel.^[4]

Safety

Isobutanol is one of the least alcohol poisoning of the butanols with an LD50 of 2460 mg/kg (rat, oral). In March 2009 the Canadian government announced its ban of isobutanol in cosmetics.^[5]

References

External links

Wikimedia Commons has media related to: Isobutanol

• 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