1,3-Butanediol

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Synonyms: 1,3-Dihydroxybutane

Abbreviation: BG, 1,3-BG

Molecular Formula: C₄H₁₀O₂

Molecular Weight: 90.12

CAS Number: 107-88-0

EINECS Number: 203-529-7

Structural Formula:

Physicochemical Properties

Colorless, transparent, hygroscopic, viscous liquid. Soluble in water, ethanol, acetone, and ethers; insoluble in aliphatic hydrocarbons, benzene, and carbon tetrachloride. Essentially odorless. Vapor density is 3.1 times that of air; explosion limits (volume fraction) in air are 1.9%–12.6%.

1,3-Butanediol has very high hygroscopicity. At relative humidities of 81%, 47%, and 20%, the moisture absorption rates at 25–28°C for 144 hours are 38.5%, 12.5%, and 1.3%, respectively.

1,3-Butanediol is non-toxic. The oral toxicity LD₅₀ for rats is 18.61 g/kg, and for mice it is 12.98 g/kg. It has virtually no skin irritation.

Properties and Uses

1,3-Butanediol is a diol containing one primary hydroxyl group and one promoting hydroxyl group. Its main use is in the production of polyester plasticizers and unsaturated polyester resins. The resulting polyester plasticizers have good compatibility and stability with many polymers. Unsaturated polyesters exhibit good weather resistance, flexibility, and impact resistance. 1,3-Butanediol is also used in the production of saturated polyester polyols for polyurethane coatings, imparting flexibility. 1,3-Butanediol is also an excellent hygroscopic/humectant agent; as a good humectant, it can be used in cat and dog food, tobacco, and cosmetics. It can also be used as a solvent in surfactants, inks, and fragrances, and as a coupling agent in cellophane.