1,4-Butanediol is an organic compound with the molecular formula C4H10O2 and a molecular weight of 90.12. It appears as a colorless or pale yellow oily liquid. It is flammable, with a freezing point of 20.1°C and a refractive index of 1.4461. It is soluble in methanol and ethanol, slightly soluble in ether. It is hygroscopic, has a bitter odor, and tastes slightly sweet when ingested.
Chinese Name: 1,4-Butanediol
English Name: Butane-1,4-diol; 
Alias: 1,4-Dihydroxybutane
Chemical Formula: C4H10O2
Molecular Weight: 90.12
CAS Registry Number: 110-63-4
EINECS Registry Number: 203-786-5
Melting Point: 20.2 °C
Water Solubility: Miscible with water
Density: 1.0171 (20/4°C)
Appearance: Colorless viscous oily liquid
Flash Point: 150 °C (closed cup)
Uses
1,4-Butanediol is an important raw material in organic and fine chemical industries, serving as a fundamental component in the production of polybutylene terephthalate (PBT) engineering plastics and PBT fibers. PBT plastic is one of the five most promising engineering plastics.
1,4-Butanediol is also a primary raw material for producing tetrahydrofuran (THF), an important organic solvent. Polymerization of THF yields polytetramethylene ether glycol (PTMEG), which is the basic raw material for producing high-elasticity spandex (Lycra fiber). Spandex is mainly used in the production of high-end sportswear, swimwear, and other high-elasticity knitted products.
Downstream products of 1,4-butanediol are used as raw materials for producing 2-pyrrolidone and N-methylpyrrolidone. These, in turn, lead to a series of high-value-added products such as vinylpyrrolidone and polyvinylpyrrolidone, which are widely used in pesticides, pharmaceuticals, and cosmetics.