Isobutanol (also known as Isobutyl Alcohol) is a branched-chain alcohol with the chemical formula C₄H₉OH. It is an isomer of butanol (along with n-butanol, sec-butanol, and tert-butanol), and is specifically a branched form of butanol where the hydroxyl group (OH) is attached to a secondary carbon atom in a branched chain. The molecular structure is different from that of n-butanol, which has a straight-chain structure. Isobutanol is a colorless, flammable liquid with a mild odor similar to butter or rubber. It is miscible with water and many organic solvents and is widely used in solvent, chemical intermediate, and fuel additive applications.
Properties of Isobutanol:
- Molecular Formula: C₄H₉OH
- IUPAC Name: 2-Methylpropan-1-ol
- Boiling Point: 108°C (226°F)
- Melting Point: -108°C (-162°F)
- Density: 0.802 g/cm³ at 20°C
- Flash Point: 35°C (95°F) – flammable
- Solubility: Soluble in water, ethanol, and ether; partially soluble in chloroform and benzene.
Key Uses of Isobutanol:
Solvent:
Isobutanol is a solvent for paints, lacquers, coatings, inks, and adhesives, particularly in high-performance coatings.
Chemical Intermediate:
Isobutanol is used in the production of butyl acetate, which is used in paint thinners and coatings. It is also a key intermediate for isobutene, which is used to make methyl tert-butyl ether (MTBE), an octane booster for gasoline, and polybutenes.
Fuel Additive:
Isobutanol is gaining attention as an alternative fuel or fuel additive due to its higher energy content and lower volatility compared to ethanol.
Flavors and Fragrances:
It is used in the production of flavors and fragrances for use in food, cosmetics, and personal care products.
Plasticizers:
Isobutanol is used in the production of plasticizers for PVC and other synthetic rubbers.