Isobutyl alcohol, CAS 78-83-1, is a clear, colourless liquid with a mild characteristic odour. It belongs to the aliphatic alcohol family and is one of the four isomeric butanols. The compound works both as an industrial solvent, dissolving resins, oils, and dyes, and as a chemical intermediate that introduces the isobutyl group into larger molecules.
What Is Another Name for Isobutyl Alcohol?
The most common alternative name is isobutanol. The systematic IUPAC name is 2-methylpropan-1-ol, and commercial documents also use 2-methyl-1-propanol, iso butanol, isopropyl carbinol, and the abbreviation IBA. Buyers may meet any of these terms on technical data sheets, safety data sheets, or customs paperwork, so recognising them as synonyms of one substance prevents duplicate sourcing and mismatched specifications.
| Name type | Term |
|---|---|
| Common commercial name | Isobutanol |
| Preferred IUPAC name | 2-methylpropan-1-ol |
| Alternative systematic name | 2-methyl-1-propanol |
| Abbreviation | IBA |
| CAS registry number | 78-83-1 |
| Molecular formula | C4H10O |
Physical Properties and Solvent Behaviour
Isobutyl alcohol has a molar mass of about 74.12 g/mol, a boiling point near 108 °C, and a flash point of about 28 °C, which puts it in the flammable liquid category. Density is roughly 0.80 g/cm³, slightly below water, and water solubility is limited to about 8.5 g per 100 mL at 20 °C. Complete miscibility with most organic solvents is what makes the material useful in blended systems where a water-miscible alcohol such as ethanol would separate or carry moisture into the film.
Moderate evaporation rate - supports flow and levelling in coatings
Partial water tolerance - tolerant of small moisture levels in pigmented systems
Good resin solvency - dissolves a wide range of natural and synthetic resins
Neutral odour profile relative to heavier alcohols - suitable for inks and cleaning blends
Ester Derivatives and Chemical Intermediates
The largest downstream derivative is isobutyl acetate, produced by esterification with acetic acid. This ester is a low-odour solvent for nitrocellulose lacquers, printing inks, and nail-care formulations, and it also serves as a flavour ingredient in the food industry. Further reactions convert the alcohol into plasticizers, lubricant additives, and amino resin crosslinkers used in baking enamels.
In pharmaceutical, agrochemical, and fragrance production the alcohol acts as a process solvent for reactions and crystallisations. Its moderate polarity and low water uptake suit water-sensitive intermediates, where the solvent must not hydrolyse the active ingredient or introduce unwanted moisture into a crystallisation step. Because the molecule is a primary alcohol, it can also be oxidised to isobutyraldehyde and isobutyric acid, both of which feed specialty chemistry routes.
Applications in Coatings, Inks and Cleaning Products
In automotive and industrial paints, isobutyl alcohol controls flow, levelling, and open time, reducing brush marks and orange peel. Inks use it to adjust viscosity and drying speed, and adhesives use it to wet out substrates before the bond sets. Cleaning formulations combine it with surfactants and other solvents to lift greases, oils, and printing residues from metal and plastic surfaces.
Formulators should note that the alcohol is a secondary consideration in some solvent blends, where its role is to fine-tune evaporation rather than to carry the bulk of the solvency load. That makes blend design, rather than the raw material itself, the key variable in achieving consistent film quality.
Storage and Handling
Keep isobutyl alcohol in tightly sealed containers in a cool, well-ventilated area away from ignition sources, heat, and strong oxidising agents. Use bonded and grounded equipment during transfer to control static, and avoid breathing vapour by relying on local exhaust ventilation or suitable respiratory protection. Wear chemical-resistant gloves and eye protection, and keep eyewash and washing facilities available nearby.
Each shipment should be accompanied by a safety data sheet and a certificate of analysis, and containers should be labelled with the common synonyms as well as the CAS number 78-83-1 so that repacked material cannot be mistaken for a different butanol isomer.
Frequently Asked Questions
Q: What is another name for isobutyl alcohol?
The most common alternative name is isobutanol, and its IUPAC name is 2-methylpropan-1-ol.
Q: What is the CAS number of isobutyl alcohol?
The CAS registry number is 78-83-1 and the molecular formula is C4H10O.
Q: What are the synonyms of isobutyl alcohol?
Synonyms include isobutanol, 2-methyl-1-propanol, 2-methylpropan-1-ol, iso butanol, and the abbreviation IBA.
Q: What is isobutyl alcohol used for?
It serves as an industrial solvent in coatings, inks, and cleaning products and as an intermediate for isobutyl acetate, plasticizers, and lubricant additives.
Q: Is isobutyl alcohol flammable?
Yes. Its closed-cup flash point is about 28 °C, so it must be handled away from ignition sources with grounded equipment.
Q: Is isobutanol the same as isopropyl alcohol?
No. Isopropyl alcohol is a three-carbon secondary alcohol, while isobutanol is a four-carbon branched primary alcohol with different solvency and boiling point.