Cas Number


Other Names


Butylene oxide

Cyclotetramethylene oxide

Diethylene oxide

Tetra-methylene oxide

The formula



Tetrahydrofuran (THF), whose preferred IUPAC name was changed in 2013 to oxolane is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is mainly used as a precursor to polymers. Being polar and having a wide liquid range, THF is a versatile solvent.

Physical and Chemical Properties
Physical state and Appearance : Liquid.
Odor : Ethereal. Fruity.
Color : Colorless.
Boiling Point : 65°C (149°F) @ 760 mm Hg
Flash point : CLOSED CUP: -14.5°C (5.9°F). OPEN CUP: -20°C (-4°F).
Melting Point : -108.3°C (-162.9°F)
Specific Gravity : 0.8892 (Water = 1)
Vapor Pressure : 19.3 kPa (@ 20°C)
Vapor Density : 2.5 (Air = 1)
Volatility : 100% (v/v).
Solubility : Easily soluble in diethyl ether, acetone. Partially soluble in cold water. Solubility in water is 30%. Miscible with alcohols, ketones, esters, hydrocarbons, and ethers. Very soluble in benzene, ethanol, and chloroform.
Water, ppm : 200 or less
Purity, % : 99.95 or more
Specific gravity (20/4°c) : 0.886~0.889
Refractive index (n20/d) : 1.406~10408
Peroxide, ppm : 200 or less

Polytetramethylene Ether Glycol (PTMEG):- THF is polymerized under strongly acidic conditions to form PTMEG which is used extensively to manufacture urethane elastomers and fibers. PTMEG provides exceptional flexibility and elasticity to such products. In particular, PTMEG based urethanes are noted for their good flex properties at low temperature and their hydrolytic resistance.

Magnetic Tape: Solvents are needed to dissolve the raw binder polymers and to provide a fluid medium for the pigment dispersion in the magnetic tape paint. THF, with its high purity, excellent solvency power and favorable conductivity value, is fast becoming the solvent of choice.

Adhesives: THF solvents can be used to join rigid plastic pipe and in compounded cements for leather, plastic sheet film extrusions and for molded plastic parts assemblies. The combined advantages of rapid solvent activity, minimum gelation and lower relative viscosities for resin solutions, makes THF an attractive solvent choice.

PVC Cements: - THF-PVC formulations meet NSF standards. THF solvent cements can be Formulated with additional solvents and inorganic fillers to control set time. THF can also function as a PVC-type cleaner before joint formation.

Vinyl Films and Cellophane: - THF is a superb solvent for many chlorinated resins which find utility in film formation applications such as vinyl topcoating, cast vinyl films, and coated cellophane.

Such applications rely on the ability of THF to solvate the polymeric resins without excessive viscosity build up. In addition, the high volatility of THF is essential in these applications because of the need to remove the solvent completely with minimal energy input.

Pharmaceutical Solvent Applications: - THF is frequently utilized as a solvent in many pharmaceutical synthetic procedures because of its broad solvency for polar and non-polar compounds. THF is particularly capable of dissolving many ionic species and organometallics which are commonly used in specialty syntheses. In many cases, THF makes higher yields and faster reaction rates possible. In addition, THF’s high volatility and very high purity facilitate solvent removal and recovery without leaving residues in the desired product.

Reaction Solvent: - THF is stable under very strongly basic conditions and is therefore the choice for numerous specialty syntheses which involve complex catalysts and Grignard reagents. Also, THF is a preferred solvent for anionic polymerization.

Miscellaneous Solvent Applications: - THF is used in very large quantities in research institutions worldwide as a solvent for numerous chromatographic techniques such as Gel Phase Chromotogoraphy. Its broad solvency capabilities are consistently reliable. Other examples of its utilization as a solvent are: Natural Products, Industrial Resins, Elastomers, Polyurethane Coatings & Printing Inks.