Tetrahydrofuran, or THF, is a common organic solvent of the ether family. A colorless, somewhat volatile liquid at room temperature, it is similar to diethyl ether, the chemical once widely used as an anesthetic, with a similar odor, but does not share its anesthetic properties. It has the chemical formula (CH2)4O and is known by a number of other names, most of which have fallen out of common use. It is popular as a solvent, as it is soluble in most other common solvents like water, alcohols, esters, and acetone, is chemically inactive, and acts as a strong solvent on many materials, particularly organics. Tetrahydrofuran is used extensively in the manufacture of many polymers as well as other products such as certain adhesives and pharmaceuticals.
This cousin to common ether can be potentially dangerous and must be handled under strictly controlled conditions for safety. It can form dangerous flammable chemicals called peroxides when exposed to air, which can ignite or explode very easily. For this reason, additives such as BHT are mixed with tetrahydrofuran to stabilize it, which reduces its tendency to spontaneously form these dangerous peroxides. THF is also stored in sealed containers with pure nitrogen gas to prevent it from reacting with air. It is also highly flammable and can give off toxic materials as a by-product of burning.
Chief among its uses is the production of certain polymers. THF is used as a precursor to the formation of many complex polymers, as its solvent properties allow for the mixing and combining of simple polymers in solution. When mixed with acids, tetrahydrofuran itself can be polymerized, and the resulting polymers have many uses, such as the manufacture of urethanes and polyurethanes. Some of these materials are very common in everyday products, like certain fabrics with elastic properties.
Its strong solvent properties make tetrahydrofuran highly suitable for many other uses, as well. It is used in making adhesives that are used with polyvinyl chloride (PVC) and for improving certain qualities of other materials, such as cellophanes and magnetic tapes, although this usage is becoming less common in the digital age as these tapes are phased out in favor of digital recording and storage media. THF is a key component in the manufacture of a class of protective coatings and is used in the production and extraction of many organic and organometallic compounds, including some drugs.