Fluoroplastics (PTFE and analogues): properties and applications / Articles

Fluoroplastics (fluoropolymers) are a class of polymeric materials based on fluorine-containing polyolefins and their copolymers. They are polymerization polymers based on tetrafluoroethylene and its copolymers with various compounds, best known under the name "fluoroplastics". Due to their unique combination of chemical inertness, thermal stability, non-stick and dielectric properties, fluoroplastics occupy a special place among all polymeric materials and find application in the most critical industries — from aerospace to medicine and food industry.

History of Discovery

The history of fluoroplastics began in 1938 when chemist Roy Plunkett, working at Kinetic Chemicals (later a DuPont subsidiary), accidentally discovered that gaseous tetrafluoroethylene pumped into cylinders under pressure had polymerized into a powder with unique properties. The patent for this polymer was issued in 1941, and commercial production began in 1947 under the trademark Teflon. In the USSR, PTFE became known during World War II when Soviet technicians dismantled a US-made tank and found a large white ring made of fluoroplastic in its turret mechanism. Since then, fluoroplastics have become one of the key materials in high-tech industries.

Chemical Structure and Classification

Fluoroplastics are polymers in which hydrogen atoms in the hydrocarbon chain are replaced by fluorine atoms. The most well-known representative is polytetrafluoroethylene (PTFE, fluoroplastic-4) — a polymer with the chemical formula (C₂F₄)ₙ. It is a fully fluorinated unbranched polymer with a carbon backbone.

In Russia, the following classification of fluoroplastics by grades is adopted:

Fluoroplastic-4 (F-4) — polytetrafluoroethylene (PTFE), the most common type. Available in various modifications: F-4M (improved impact strength), F-4A, F-4D, F-4MB and others.
Fluoroplastic-3 (F-3) — polychlorotrifluoroethylene (PCTFE).
Fluoroplastic-40 (F-40) — copolymer of tetrafluoroethylene and ethylene.
Fluoroplastic-2 (F-2) — polyvinylidene fluoride (PVDF).

In global practice, in addition to PTFE, the following fluoropolymers are widely known:

FEP (fluorinated ethylene propylene) — copolymer of tetrafluoroethylene and hexafluoropropylene.
PFA (perfluoroalkoxy) — copolymer of tetrafluoroethylene with perfluorovinyl ether.
ETFE — copolymer of ethylene and tetrafluoroethylene.
PVDF (polyvinylidene fluoride) — used for membranes for filtration of organic acids and alkalis, as well as in air HEPA filters.
FKM (fluoroelastomer) — fluorine-containing elastomer.
FFKM (perfluoroelastomer) — possesses chemical resistance similar to PTFE and high heat resistance.

Physical and Mechanical Properties of PTFE

PTFE (fluoroplastic-4) possesses a unique set of properties, many of which are record-breaking among polymers:

Chemical Resistance. PTFE is inert to chemically aggressive environments. It does not oxidize and is not subject to corrosion. PTFE is resistant to virtually all chemicals, except molten alkali metals, fluorine and some fluorinating agents at high temperatures. This makes it indispensable for chemical engineering.

Thermal Resistance. PTFE can be used in an exceptionally wide temperature range: from -269 °C to +260 °C, and briefly up to 300–400 °C. The melting point of crystallites is about 327 °C. Fluoroplastic-40 has an operating range from -100 to 280 °C.

Anti-friction Properties. Fluoroplastic-4 is listed in the Guinness Book of Records as the most slippery material. It has a very low coefficient of friction, hydrophobicity and non-stick properties. PTFE is widely used as a base for composites for manufacturing parts of critical friction assemblies — bearings, bridge supports and others. It is indispensable in "dry" friction assemblies due to its self-lubricating properties.

Dielectric Properties. PTFE is an excellent dielectric with very low dielectric losses. This property makes it indispensable in the electrical and electronic industries.

Water Repellent Properties. PTFE does not absorb water, has low water absorption and gas permeability.

Biocompatibility. PTFE is physiologically neutral, allowing its use in medicine and the food industry.

Disadvantages of PTFE

Despite its unique properties, PTFE also has significant disadvantages:

Low wear resistance — requires modification with fillers for use in friction assemblies.
High coefficient of linear thermal expansion.
High deformability and creep (cold flow) — PTFE rapidly accumulates plastic deformation under both constant and cyclic loads.
Difficult processing — PTFE is not thermoplastic in the usual sense as it does not transition to a viscous-flow state; processing is carried out by cold pressing followed by sintering.

Modification of PTFE

To improve properties and expand the scope of application, various fillers are introduced into PTFE: carbon and glass fibres, metal oxides, silicates, detonation nanodiamonds, bronze powders, molybdenum disulphide, graphite, coke, mica, copper, boron nitride. Filled composites (e.g., F-4K20 with coke filler) significantly expand the range of mechanical loads and operating conditions.

Comparison of PTFE with Melt-Processable Fluoropolymers

Unlike PTFE, fluoropolymers such as FEP and PFA are thermoplastic and can be processed by injection moulding, extrusion and compression moulding. PFA is preferable to FEP in high-temperature applications. PFA is also resistant to creep, unlike PTFE.

Production

Production of fluoroplastic-4 is carried out in three stages:

Production of chlorodifluoromethane by the Swarts reaction.
Tetrafluoroethylene is obtained from chlorodifluoromethane by pyrolysis.
Fluoroplastic powder is formed as a result of tetrafluoroethylene polymerization.

Polymerisation can be carried out by suspension or emulsion methods. In suspension polymerisation, the polymer is obtained as a powder with a particle size of 50–500 μm, in emulsion polymerisation — 0.25 μm. For the production of blanks, cold pressing followed by sintering at 365 °C is used. Fluoroplastic-40 is produced by emulsion polymerisation.

Applications

Thanks to the unique combination of properties, fluoroplastics are used in almost all industries:

Chemical and Petrochemical Industry. PTFE is used for seals, gaskets, linings of pipes and vessels operating with aggressive media. Fluoroplastic coatings are used for corrosion protection of petrochemical equipment.

Mechanical Engineering. PTFE and its composites are used for plain bearings, sealing rings, piston rings, bushings and other friction assembly parts. PTFE parts have lower weight, are resistant to low temperatures and aggressive media, and operate almost silently.

Electrical and Electronics. Thanks to outstanding dielectric properties, PTFE is used for wire and cable insulation, including for aviation and aerospace applications. Fluoroplastic-40 has properties that allow its use in cable production for special conditions such as space applications.

Aerospace and Aviation. Fluoroplastics are used for high-temperature parts, seals and insulation.

Medicine. Thanks to biocompatibility and physiological neutrality, PTFE is used for implants, medical tubes, catheters and other products in contact with human tissues.

Food Industry and Household Appliances. PTFE is widely known as a material for non-stick coatings of cookware (Teflon coatings). It is also used for lining rolls for dough rolling and other non-stick coatings.

Construction. Used as a sealing and anti-friction material.

Global PTFE Market

The global polytetrafluoroethylene market shows steady growth. In 2025, the market was valued at USD 1.95 billion, with projections to reach USD 3.27 billion by 2034 at a CAGR of 5.9%. In physical terms, the market was 224.82 kilotons in 2025, with forecasts of growth to 290.73 kilotons by 2031 (CAGR 4.38%).

The Asia-Pacific region dominates the PTFE market with a 56% share in 2025. Key growth drivers include the expansion of the electronics industry (including 5G technologies and electric vehicles), capacity growth in the semiconductor industry, and increased chemical processing capacity. Key market players include 3M, AGC Inc., Daikin America, Gujarat Fluorochemicals and Dongyue Group.

At the same time, the market faces challenges related to environmental regulation of PFAS (per- and polyfluoroalkyl substances). The European Chemicals Agency proposed restrictions on PFAS in 2025, which could affect broad classes of fluoropolymers. Major manufacturers are launching PFAS-compliant or fluorine-free product lines.

Conclusion

Fluoroplastics, and primarily polytetrafluoroethylene (PTFE, fluoroplastic-4), represent a unique class of polymeric materials with exceptional chemical resistance, thermal stability, anti-friction and dielectric properties. Despite disadvantages such as difficult processing and creep tendency, fluoroplastics remain indispensable in the chemical, electrical, aerospace, medical and food industries. The development of modification technologies and the emergence of new fluoropolymer grades expand the application area of these unique materials, although tightening environmental regulation creates new challenges for the industry.