PTFE Polytetrafluoroethylene

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PTFE is a polymer similar to polyethylene, in which hydrogen atoms have been replaced by fluorine atoms. The chemical formula of the monomer, tetrafluoroethylene, is CF2=CF2. Under the name Teflon, the multinational company DuPont commercializes this and four other polymers with a similar molecular structure and properties. Among them are PFA resin (perfluoroalkoxy) and FEP copolymer (Fluorinated Ethylene Propylene), called PFA and FEP respectively. Both PFA and FEP share the characteristic properties of PTFE, offering greater ease of manipulation in industrial applications.

The main virtue of this material is that it is practically inert, it does not react with other chemicals except in very specific situations. This is mainly due to the protection of fluorine atoms on the carbon chain. This lack of reactivity makes its toxicity practically nil, and it is, in fact, the material with the lowest known coefficient of friction. Another characteristic quality is its impermeability, maintaining its qualities in humid environments.

It is also a great electrical insulator and extremely flexible, it is not altered by the action of light and is capable of withstanding temperatures from -270°C (3 K) to 300°C (573 K). Its most well-known quality is its non-stick property.

One of the first uses of this material was in the Manhattan Project as a coating for valves and as a sealant in tubes containing uranium hexafluoride (highly radioactive material).

PTFE has multiple applications, although it was not initially marketed (it was not sold until 1946). Some of them are mentioned below:

In coatings for airplanes, rockets, and spacecraft due to its ability to withstand large temperature differences.
In the industry, it is used in articulated elements, as its anti-friction capacity allows the elimination of lubricants such as Krytox.
In medicine, taking advantage of its non-reactivity with substances or tissues and its flexibility and non-stick properties, it is used for prostheses, the creation of artificial tissues and blood vessels, and even aesthetic surgeries (body piercing).
In electronics, as a coating for cables or as a dielectric for capacitors due to its high insulating capacity and temperature resistance. Capacitors with PTFE dielectric are used in high-quality sound amplifiers. They produce the least audio frequency distortions. Slightly less efficient are those with metallized polyester (MKP) dielectric.
In kitchen utensils, such as pans and pots, due to its low friction capacity, making them easy to clean and maintaining a lower degree of toxicity.
In paints and varnishes.
In structures and elements subjected to corrosive environments, as well as in hoses and ducts through which chemical products circulate.
As a coating for armor-piercing bullets. PTFE does not affect the missile’s penetration, but it reduces friction with the interior of the weapon to decrease wear.