Methyl isobutyl ketone (MIBK) is the common name for the organic compound 4-methylpentan-2-one, condensed chemical formula (CH₃)₂CHCH₂C(O)CH₃. This colourless liquid, a

ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bo ...

, is used as a solvent for gums, resins, paints, varnishes, lacquers, and nitrocellulose.

Production

At laboratory scale, MIBK can be produced via a three-step process using acetone as the starting material. Self-condensation, a type of aldol reaction, produces diacetone alcohol, which readily dehydrates to give 4-methylpent-3-en-2-one (commonly, mesityl oxide). Mesityl oxide is then hydrogenated to give MIBK. : Industrially, these three steps are combined. Acetone is treated with a strongly acidic,

palladium catalyst Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself na ...

-doped cation exchange resin under medium pressure of hydrogen. Several million kilograms are produced annually.Stylianos Sifniades, Alan B. Levy, "Acetone" in ''Ullmann’s Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2005.

Uses

MIBK is used as a solvent for nitrocellulose, lacquers, and certain polymers and resins.

Precursor to 6PPD

Another major use is as a precursor to ''N''-(1,3-dimethylbutyl)-''N-phenyl-''p''-phenylene diamine (

6PPD 6PPD is an organic chemical widely used as stabilising additive (or antidegradant) in rubbers, such as NR, SBR and BR; all of which are common in vehicle tires. Although it is an effective antioxidant it is primarily used because of its excell ...

), an antiozonant used in tires. 6PPD is prepared by reductive coupling of MIBK with 4-aminodiphenylamine.

Solvent and niche applications

Unlike the other common ketone solvents, acetone and MEK, MIBK has quite low solubility in water, making it useful for liquid-liquid extraction. It has a similar

polarity Polarity may refer to: Science * Electrical polarity, direction of electrical current * Polarity (mutual inductance), the relationship between components such as transformer windings * Polarity (projective geometry), in mathematics, a duality of o ...

to ethyl acetate, but greater stability towards aqueous

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...

and base. It can be used to extract gold, silver and other precious metals from

cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of a ...

solutions, such as those found at gold mines, to determine the levels of those dissolved metals.

Diisobutyl ketone 2,5-Dimethylhexane is a branched alkane used in the aviation industry in low revolutions per minute helicopters. As an isomer of octane, the boiling point is very close to that of octane, but can in pure form be slightly lower. 2,5-Dimethylhexane ...

(DIBK), a related lipophilic ketone, is also used for this purpose. Methyl isobutyl ketone is also used as a denaturing agent for denatured alcohol. When mixed with water or isopropyl alcohol MIBK serves as a developer for PMMA electron beam lithography resist. MIBK is used as a solvent for CS in the preparation of the CS spray used currently by American and British police forces.

References

External links

International Chemical Safety Card 0511

* ttps://www.cdc.gov/niosh/npg/npgd0326.html NIOSH Pocket Guide to Chemical Hazards {{Authority control Hazardous air pollutants Hexanones Ketone solvents Commodity chemicals IARC Group 2B carcinogens