Tetrahydrofuran, or THF is a colorless, volatile cycloaliphatic ether with an odor characteristic of acetone. It is chemically neutral, highly polar and miscible with water. Synthetically derived THF is made by eliminating water from 1,4-butanediol. THF has excellent solvent power for numerous organic substances. It is miscible with water and all common organic solvents.
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.
Since THF is very soluble in water and has a relatively low boiling point, signficant amounts are often released into the environment, causing contamination problems. It is not considered to be readily degradable, and concerns of environmental contamination have been raised.
Bernhardt and Diekmann performed studied the pathway for THF degradation by Rhodococcus ruber DSM 44190. The pathway shown below is hypothetical. Not all intermediates were detected(e.g. 2-hydroxytetrahydrofuran). In fact, the isomerization of this chemcial might occur spontaneously and not require an enzyme. However, degradation experiments using the same organism were performed with a similar compound, 2,5-dimethyltetrahydrofuran, and those data support the proposed tetrahydrofuran(CAS No. 109-99-9) pathway.
THF 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.