Polytetrahydrofuran, also called poly(tetramethylene ether) glycol or poly(tetramethylene oxide), is a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with formula ()_''n''OH₂ or HO-(-(CH₂)₄O-)_''n''-H. It can be viewed as a polymer of

tetrahydrofuran Tetrahydrofuran (THF), or 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 ...

, or as the

polyether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be ...

derived from 1,4-butanediol. The product is commercially available as polymers of low average

molecular weight A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bio ...

s, between 250 and 3000 daltons. In this form it is a white waxy solid that melts between 20 and 30 °C. The commercial product can be processed further into polymers with molecular weights of 40,000 and higher. The product is sold under various trade names including Terathane from

Invista Invista (stylized as INVISTA), headquartered in Wichita, Kansas, United States, is a fiber, resin and intermediates company. It has about 10,000 employees in over 20 countries worldwide. The predecessor DuPont Textiles and Interiors was formed fr ...

and PolyTHF from

BASF BASF SE () is a German multinational chemical company and the largest chemical producer in the world. Its headquarters is located in Ludwigshafen, Germany. The BASF Group comprises subsidiaries and joint ventures in more than 80 countries ...

. The BASF plant in

Ludwigshafen Ludwigshafen, officially Ludwigshafen am Rhein (; meaning " Ludwig's Port upon Rhine"), is a city in the German state of Rhineland-Palatinate, on the river Rhine, opposite Mannheim. With Mannheim, Heidelberg, and the surrounding region, it ...

at one point was producing 250,000 metric tons per year. Polytetrahyrofuran polyethylene glycol can be controlled for export from the U.S. under the Export Administration Regulations on th
Commerce Control List
and/or on export control regulations based on th
Wassenaar Arrangement
(ECCN: 1C111.b.5). Under these regulations export/transfer of the product may require a license or export authorization.

Applications

Container 【 22T6 】 CCRU 164132(1) 【 Pictures taken in Japan 】

The main use of polytetrahydrofuran is to make

elastic Elastic is a word often used to describe or identify certain types of elastomer, elastic used in garments or stretchable fabrics. Elastic may also refer to: Alternative name * Rubber band, ring-shaped band of rubber used to hold objects togethe ...

fibres such as spandex (elastane) for stretchable

fabric Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not ...

s and for polyurethane resins. The latter are polyurethane prepolymers dissolved in solvent. They are used in the manufacture of artificial leather. These elastomers are either polyurethanes made by reacting PTMEG with di isocyanates, or

polyester Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include natura ...

s made by reacting PTMEG with diacids or their derivatives. The polymer is also a starting material for

thermoplastic A thermoplastic, or thermosoft plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight. The polymer chains associate ...

polyurethane Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from ...

, thermoplastic polyesters, polyetheramide and cast polyurethane elastomers, used for instance in the wheels of

roller skates Roller skates, are shoes or bindings that fit onto shoes that are worn to enable the wearer to roll along on wheels. The first roller skate was an inline skate design, effectively an ice skate with wheels replacing the blade. Later the "quad s ...

and

skateboard A skateboard is a type of sports equipment used for skateboarding. They are usually made of a specially designed 7-8 ply maple plywood deck and polyurethane wheels attached to the underside by a pair of skateboarding trucks. The skateboarder ...

Synthesis

Polytetrahydrofuran is commonly prepared by acid-catalyzed

polymerization In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many f ...

of tetrahydrofuran. The starting material is natural gas, which is converted to

acetylene Acetylene ( systematic name: ethyne) is the chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure ...

, then reacted with

formaldehyde Formaldehyde ( , ) ( systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section ...

to make butynediol and then butanediol. The latter is turned into tetrahydrofuran by action of a

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

and then polymerized. PTMEG synthesis

References

{{reflist Diols Polyethers