Polytetrafluoroethylene (PTFE) is a synthetic

fluoropolymer A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. The best known fluoropolymer is polytetrafluoroethylene under the brand name "Teflon ...

tetrafluoroethylene Tetrafluoroethylene (TFE) is a fluorocarbon with the chemical formula C2 F4. It is the simplest perfluorinated alkene. This gaseous species is used primarily in the industrial preparation of fluoropolymers. Properties Tetrafluoroethylene is a ...

that has numerous applications. It is one of the best-known and widely applied

PFAS Per- and polyfluoroalkyl substances (PFASs) are synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain. An early definition, from 2011, required that they contain at least one perfluoroalkyl mo ...

. The commonly known brand name of PTFE-based composition is Teflon by

Chemours Chemours (, ) is an American chemical company that was founded in July 2015 as a spin-off from DuPont. It has its corporate headquarters in Wilmington, Delaware, United States. History In October 2013, DuPont announced that it was planning to ...

, a spin-off from

DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...

, which originally discovered the compound in 1938. Polytetrafluoroethylene is a

fluorocarbon Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often has distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Fluorocarbons and their derivatives are commerci ...

solid, as it is a high-

molecular-weight The molecular mass (''m'') is the mass of a given molecule: it is measured in daltons (Da or u). Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The related quanti ...

polymer consisting wholly of

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...

and

fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reacti ...

. PTFE is

hydrophobic In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water. Hydrophobic molecules tend to be nonpolar and, th ...

: neither water nor water-containing substances wet PTFE, as fluorocarbons exhibit only small

London dispersion force London dispersion forces (LDF, also known as dispersion forces, London forces, instantaneous dipole–induced dipole forces, fluctuating induced dipole bonds or loosely as van der Waals forces) are a type of intermolecular force acting between at ...

s due to the low

electric polarizability Polarizability usually refers to the tendency of matter, when subjected to an electric field, to acquire an electric dipole moment in proportion to that applied field. It is a property of all matter, considering that matter is made up of elementar ...

of fluorine. PTFE has one of the lowest coefficients of

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of t ...

of any solid. Polytetrafluoroethylene is used as a

non-stick coating A non-stick surface is engineered to reduce the ability of other materials to stick to it. Non-stick cookware is a common application, where the non-stick coating allows food to brown without sticking to the pan. Non-stick is often used to refer ...

for pans and other cookware. It is non-reactive, partly because of the strength of

carbon–fluorine bond The carbon–fluorine bond is a polar covalent bond between carbon and fluorine that is a component of all organofluorine compounds. It is one of the strongest single bonds in chemistry (after the B–F single bond, Si–F single bond, and H–F s ...

s, so it is often used in containers and pipework for reactive and corrosive chemicals. Where used as a

lubricant A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...

, PTFE reduces friction, wear, and energy consumption of machinery. It is used as a graft material in surgery and as a coating on

catheter In medicine, a catheter (/ˈkæθətər/) is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Cath ...

History

Polytetrafluoroethylene was accidentally discovered in 1938 by

Roy J. Plunkett Roy J. Plunkett (June 26, 1910 – May 12, 1994) was an American chemist. He discovered polytetrafluoroethylene (PTFE), better known as Teflon, in 1938. Personal life and education Plunkett was born in New Carlisle, Ohio and attended Newton Hig ...

while he was working in New Jersey for

. As Plunkett attempted to make a new

chlorofluorocarbon Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivatives of methane, ethane, and prop ...

refrigerant, the

gas in its pressure bottle stopped flowing before the bottle's weight had dropped to the point signaling "empty". Since Plunkett was measuring the amount of gas used by weighing the bottle, he became curious as to the source of the weight, and finally resorted to sawing the bottle apart. He found the bottle's interior coated with a waxy white material that was oddly slippery. Analysis showed that it was polymerized perfluoroethylene, with the iron from the inside of the container having acted as a catalyst at high pressure. Kinetic Chemicals patented the new fluorinated plastic (analogous to the already known

polyethylene Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including bo ...

) in 1941, and registered the Teflon trademark in 1945. By 1948, DuPont, which founded Kinetic Chemicals in partnership with

General Motors The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...

, was producing over two million pounds (900 tons) of Teflon brand Polytetrafluoroethylene per year in

Parkersburg, West Virginia Parkersburg is a city in and the county seat of Wood County, West Virginia, Wood County, West Virginia. Located at the confluence of the Ohio River, Ohio and Little Kanawha River, Little Kanawha rivers, it is the state's fourth-largest city and ...

. An early use was in the

Manhattan Project The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project w ...

as a material to coat valves and seals in the pipes holding highly reactive

uranium hexafluoride Uranium hexafluoride (), (sometimes called "hex") is an inorganic compound with the formula UF6. Uranium hexafluoride is a volatile white solid that reacts with water, releasing corrosive hydrofluoric acid. The compound reacts mildly with alumin ...

at the vast

K-25 K-25 was the codename given by the Manhattan Project to the program to produce enriched uranium for atomic bombs using the gaseous diffusion method. Originally the codename for the product, over time it came to refer to the project, the prod ...

uranium enrichment Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238U ...

plant in

Oak Ridge, Tennessee Oak Ridge is a city in Anderson and Roane counties in the eastern part of the U.S. state of Tennessee, about west of downtown Knoxville. Oak Ridge's population was 31,402 at the 2020 census. It is part of the Knoxville Metropolitan Area. Oak ...

. In 1954, Colette Grégoire, the wife of French engineer Marc Grégoire, urged him to try the material he had been using on fishing tackle on her cooking pans. He subsequently created the first PTFE-coated,

non-stick pans Cookware and bakeware is food preparation equipment, such as cooking pots, pans, baking sheets etc. used in kitchens. Cookware is used on a stove or range cooktop, while bakeware is used in an oven. Some utensils are considered both cookware ...

under the brand name

Tefal Tefal S.A.S. (a portmanteau of TEFlon and ALuminium.) is a French cookware and small appliance manufacturer, owned by Groupe SEB (a global manufacturer of cookware) since 1968. The company is known for creating the non-stick cookware categor ...

(combining "Tef" from "Teflon" and "al" from aluminium).Teflon History
, ''home.nycap.rr.com'', Retrieved 25 January 2009. In the United States,

Marion A. Trozzolo Marion A. Trozzolo (1925 – June 30, 1992) was an innovator, inventor, entrepreneur, and professor of business at Rockhurst University in Kansas City, Missouri. He was the first manufacturer of teflon coated cookware in the United States, an ...

, who had been using the substance on scientific utensils, marketed the first US-made PTFE-coated pan, "The Happy Pan", in 1961.Robbins, William (21 December 1986)
Teflon Maker: Out Of Frying Pan Into Fame
, ''

New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid d ...

'', Retrieved 21 December 1986 (Subscription) Non-stick cookware has since become a common household product, now offered by hundreds of manufacturers across the world. The brand name Zepel was used for promoting its stain-resistance and water-resistance when applied to fabrics. In the 1990s, it was found that PTFE could be radiation

cross-linked In chemistry and biology a cross-link is a bond or a short sequence of bonds that links one polymer chain to another. These links may take the form of covalent bonds or ionic bonds and the polymers can be either synthetic polymers or natural ...

above its melting point in an oxygen-free environment.

Electron beam processing Electron-beam processing or electron irradiation (EBI) is a process that involves using electrons, usually of high energy, to treat an object for a variety of purposes. This may take place under elevated temperatures and nitrogen atmosphere. Poss ...

is one example of radiation processing. Cross-linked Polytetrafluoroethylene has improved high-temperature mechanical properties and radiation stability. This was significant because, for many years, irradiation at ambient conditions has been used to break down Polytetrafluoroethylene for recycling. This radiation-induced

chain scission Chain scission is a term used in polymer chemistry describing the degradation of a polymer main chain. It is often caused by thermal stress (heat) or ionizing radiation (e.g. light, UV radiation or gamma radiation), often involving oxygen. Durin ...

allows it to be more easily reground and reused. Corona discharge treatment of the surface to increase the energy and improve adhesion has been reported.

Production

PTFE is produced by

free-radical In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spont ...

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

. The net equation is : ''n'' F₂C=CF₂ → −(F₂C−CF₂)_''n''− Because tetrafluoroethylene can explosively decompose to

tetrafluoromethane Tetrafluoromethane, also known as carbon tetrafluoride or R-14, is the simplest perfluorocarbon ( C F4). As its IUPAC name indicates, tetrafluoromethane is the perfluorinated counterpart to the hydrocarbon methane. It can also be classified as a h ...

(CF₄) and carbon, special apparatus is required for the polymerization to prevent hot spots that might initiate this dangerous side reaction. The process is typically initiated with

persulfate A persulfate (sometimes known as peroxysulfate or peroxodisulfate) is a compound containing the anions or . The anion contains one peroxide group per sulfur center, whereas in , the peroxide group bridges the sulfur atoms. In both cases, sulfu ...

, which homolyzes to generate sulfate radicals: : ₃SO−OSO₃sup>2− ⇌ 2 The resulting polymer is terminated with

sulfate ester Organosulfates are a class of organic compounds sharing a common functional group with the structure R-O-SO3−. The SO4 core is a sulfate group and the R group is any organic residue. All organosulfates are formally esters derived from alcohols ...

groups, which can be hydrolyzed to give OH

end-group End groups are an important aspect of polymer synthesis and characterization. In polymer chemistry, they are functional groups that are at the very ends of a macromolecule or oligomer (IUPAC). In polymer synthesis, like condensation polymerizati ...

s.Carlson, D. Peter and Schmiegel, Walter (2000) "Fluoropolymers, Organic" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim. Granular PTFE is produced via suspension polymerization, where PTFE is suspended in an aqueous medium primarily via agitation and sometimes with the use of a surfactant such as

perfluorooctanesulfonic acid Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man-ma ...

(PFOS) or

FRD-903 FRD-903 (also known as hexafluoropropylene oxide dimer acid, HFPO-DA, and 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid) is a chemical compound that is among the class of per- and polyfluoroalkyl substances (PFASs). More specifically, t ...

(GenX). PTFE is also synthesized via emulsion polymerization, where a surfactant is the primary means of keeping PTFE in an aqueous medium.

Properties

PTFE is a

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 ...

polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

, which is a white solid at room temperature, with a density of about 2200 kg/m³ and a melting point of .Fluoroplastic Comparison – Typical Properties
Chemours.com, Retrieved 16 January 2018. It maintains high strength, toughness and self-lubrication at low temperatures down to , and good flexibility at temperatures above .Teflon PTFE Properties Handbook
Retrieved 11 October 2012. PTFE gains its properties from the aggregate effect of carbon-fluorine bonds, as do all fluorocarbons. The only chemicals known to affect these carbon-fluorine bonds are highly reactive metals like the

alkali metal The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names ...

s, and at higher temperatures also such metals as aluminum and magnesium, and fluorinating agents such as

xenon difluoride Xenon difluoride is a powerful fluorinating agent with the chemical formula , and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture-sensitive. It decomposes on contact with water vapor, but is otherwis ...

and

cobalt(III) fluoride Cobalt(III) fluoride is the inorganic compound with the formula . Hydrates are also known. The anhydrous compound is a hygroscopic brown solid. It is used to synthesize organofluorine compounds. The related cobalt(III) chloride is also known but ...

. At temperatures above PTFE undergoes depolymerization. The

coefficient of friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of ...

of plastics is usually measured against polished steel. PTFE's coefficient of friction is 0.05 to 0.10, which is the third-lowest of any known solid material (

aluminium magnesium boride Aluminum magnesium boride or Al3Mg3B56 colliqually known as BAM is a chemical compound of aluminium, magnesium and boron. Whereas its nominal formula is AlMgB14, the chemical composition is closer to Al0.75Mg0.75B14. It is a ceramic alloy that is h ...

(BAM) being the first, with a coefficient of friction of 0.02;

diamond-like carbon Diamond-like carbon (DLC) is a class of amorphous carbon material that displays some of the typical properties of diamond. DLC is usually applied as coatings to other materials that could benefit from such properties. DLC exists in seven diffe ...

being second-lowest at 0.05). PTFE's resistance to

van der Waals force In molecular physics, the van der Waals force is a distance-dependent interaction between atoms or molecules. Unlike ionic or covalent bonds, these attractions do not result from a chemical electronic bond; they are comparatively weak and th ...

s means that it is the only known surface to which a

gecko Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos ar ...

cannot stick.Research into Gecko Adhesion
, ''

Berkeley Berkeley most often refers to: *Berkeley, California, a city in the United States **University of California, Berkeley, a public university in Berkeley, California * George Berkeley (1685–1753), Anglo-Irish philosopher Berkeley may also refer ...

'', 2007-10-14. Retrieved 8 April 2010. In fact, PTFE can be used to prevent insects from climbing up surfaces painted with the material. PTFE is so slippery that insects cannot get a grip and tend to fall off. For example, PTFE is used to prevent ants from climbing out of formicaria. Because of its superior chemical and thermal properties, PTFE is often used as a gasket material within industries that require resistance to aggressive chemicals such as pharmaceuticals or chemical processing. However, until the 1990s, PTFE was not known to crosslink like an

elastomer An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of ''elastic p ...

, due to its chemical inertness. Therefore, it has no "memory" and is subject to

creep Creep, Creeps or CREEP may refer to: People * Creep, a creepy person Politics * Committee for the Re-Election of the President (CRP), mockingly abbreviated as CREEP, an fundraising organization for Richard Nixon's 1972 re-election campaign Art ...

. Because of the propensity to creep, the long-term performance of such seals is worse than for elastomers that exhibit zero, or near-zero, levels of creep. In critical applications,

Belleville washer A Belleville washer, also known as a coned-disc spring, conical spring washer, disc spring, Belleville spring or cupped spring washer, is a conical shell which can be loaded along its axis either statically or dynamically. A Belleville washer is ...

s are often used to apply continuous force to PTFE gaskets, thereby ensuring a minimal loss of performance over the lifetime of the gasket. PTFE is an

Ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...

(UV) transparent polymer. However, when exposed to an

excimer laser An excimer laser, sometimes more correctly called an exciplex laser, is a form of ultraviolet laser which is commonly used in the production of microelectronic devices, semiconductor based integrated circuits or "chips", eye surgery, and microm ...

beam it severely degrades due to heterogeneous

photothermal effect Photothermal effect is a phenomenon associated with electromagnetic radiation. It is produced by the photoexcitation of material, resulting in the production of thermal energy (heat). It is sometimes used during treatment of blood vessel lesions, l ...

Processing

Processing PTFE can be difficult and expensive, because the high melting temperature, , is above the initial decomposition temperature, . Even when molten, PTFE does not flow due to its exceedingly high melt-viscosity. The viscosity and melting point can be decreased by inclusion of small amount of

comonomer In polymer chemistry, a comonomer refers to a polymerizable precursor to a copolymer aside from the principal monomer. In some cases, only small amounts of a comonomer are employed, in other cases substantial amounts of comonomers are used. Furthe ...

s such as perfluoro (propylvinyl ether) and

hexafluoropropylene Hexafluoropropylene is the fluoroalkene with the formula CF3CF=CF2. It is the perfluorocarbon counterpart to the hydrocarbon propylene. It is mainly used to produce copolymers with tetrafluoroethylene. Hexafluoropropylene is used as a chemical i ...

(HFP). These cause the otherwise perfectly linear PTFE chain to become branched, reducing its crystallinity. Some PTFE parts are made by cold-moulding, a form of

compression molding Compression molding is a method of molding in which the molding material, generally preheated, is first placed in an open, heated mold cavity. The mold is closed with a top force or plug member, pressure is applied to force the material int ...

. Here, fine powdered PTFE is forced into a mould under high pressure (10–100 MPa). After a settling period, lasting from minutes to days, the mould is heated at , allowing the fine particles to fuse ( sinter) into a single mass.

Applications and uses

Wire insulation, electronics

The major application of PTFE, consuming about 50% of production, is for the insulation of wiring in aerospace and computer applications (e.g. hookup wire, coaxial cables). This application exploits the fact that PTFE has excellent

dielectric In electromagnetism, a dielectric (or dielectric medium) is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the mate ...

properties, specifically low

group velocity dispersion In optics, group velocity dispersion (GVD) is a characteristic of a dispersive medium, used most often to determine how the medium will affect the duration of an optical pulse traveling through it. Formally, GVD is defined as the derivative of the ...

,Extract of page 574
/ref> especially at high

radio frequencies Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper ...

, making it suitable for use as an excellent insulator in connector assemblies and

cable Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...

s, and in

printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...

s used at

microwave Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...

frequencies. Combined with its high melting temperature, this makes it the material of choice as a high-performance substitute for the weaker, higher dispersion and lower-melting-point

commonly used in low-cost applications.

Bearings seals

In industrial applications, owing to its low friction, PTFE is used for

plain bearing A plain bearing, or more commonly sliding contact bearing and slide bearing (in railroading sometimes called a solid bearing, journal bearing, or friction bearing), is the simplest type of bearing, comprising just a bearing surface and no rolli ...

gear A gear is a rotating circular machine part having cut teeth or, in the case of a cogwheel or gearwheel, inserted teeth (called ''cogs''), which mesh with another (compatible) toothed part to transmit (convert) torque and speed. The basic pr ...

slide plate A slide plate is a linear bearing that may be part of the expansion joints of bridges, high temperature horizontal ducts of water-tube boilers and other mechanical or structural engineering applications. In each case one plate is fixed and the oth ...

s, seals, gaskets, bushings, and more applications with sliding action of parts, where it outperforms

acetal In organic chemistry, an acetal is a functional group with the connectivity . Here, the R groups can be organic fragments (a carbon atom, with arbitrary other atoms attached to that) or hydrogen, while the R' groups must be organic fragments no ...

and

nylon Nylon is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic. Nylon is a silk-like thermoplastic, generally made from petro ...

Electrets

Its extremely high bulk

resistivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...

makes it an ideal material for fabricating long-life

electret An electret (formed as a portmanteau of ''electr-'' from "electricity" and ''-et'' from "magnet") is a dielectric material that has a quasi-permanent electric charge or dipole polarisation. An electret generates internal and external electric fi ...

s, the

electrostatic Electrostatics is a branch of physics that studies electric charges at rest (static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber ...

analogues of

permanent magnets A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, ...

Composites

PTFE film is also widely used in the production of carbon fiber composites as well as fiberglass composites, notably in the aerospace industry. PTFE film is used as a barrier between the carbon or fiberglass part being built, and breather and bagging materials used to incapsulate the bondment when debulking (vacuum removal of air from between layers of laid-up plies of material) and when curing the composite, usually in an autoclave. The PTFE, used here as a film, prevents the non-production materials from sticking to the part being built, which is sticky due to the carbon-graphite or fiberglass plies being pre-pregnated with

bismaleimide Maleimide is a chemical compound with the formula H2C2(CO)2NH (see diagram). This unsaturated imide is an important building block in organic synthesis. The name is a contraction of maleic acid and imide, the -C(O)NHC(O)- functional group. Malei ...

resin. Non-production materials such as Teflon, Airweave Breather and the bag itself would be considered F.O.D. (foreign object debris/damage) if left in layup.

Gore-Tex Gore-Tex is a waterproof, breathable fabric membrane and registered trademark of W. L. Gore & Associates. Invented in 1969, Gore-Tex can repel liquid water while allowing water vapor to pass through and is designed to be a lightweight, waterpr ...

is a brand of expanded PTFE (ePTFE), a material incorporating a fluoropolymer membrane with micropores. The roof of the

Hubert H. Humphrey Metrodome The Hubert H. Humphrey Metrodome (commonly called the Metrodome) was a domed sports stadium located in downtown Minneapolis, Minnesota. It opened in 1982 as a replacement for Metropolitan Stadium, the former home of the National Football League ...

Minneapolis Minneapolis () is the largest city in Minnesota, United States, and the county seat of Hennepin County. The city is abundant in water, with thirteen lakes, wetlands, the Mississippi River, creeks and waterfalls. Minneapolis has its origins ...

, US, was one of the largest applications of PTFE coatings. of the material was used in the creation of the white double-layered PTFE-coated fiberglass dome.

Chemically inert liners

Because of its extreme non-reactivity and high temperature rating, PTFE is often used as the liner in

hose A hose is a flexible hollow tube designed to carry fluids from one location to another. Hoses are also sometimes called ''pipes'' (the word ''pipe'' usually refers to a rigid tube, whereas a hose is usually a flexible one), or more generally '' ...

assemblies,

expansion joint An expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials, and vibration, or to allow movement due to ground settlement or seis ...

s, and in industrial pipe lines, particularly in applications using acids, alkalis, or other chemicals. Its frictionless qualities allow improved flow of highly viscous liquids, and for uses in applications such as brake hoses.

Musical instruments

PTFE is often found in musical instrument lubrication products; most commonly, valve oil.

Lubricants

PTFE is used in some aerosol lubricant sprays, including in micronized and polarized form. It is notable for its extremely low coefficient of friction, its hydrophobia (which serves to inhibit rust), and for the dry film it forms after application, which allows it to resist collecting particles that might otherwise form an abrasive paste. Brands include GT85. Teflon-jar hg

Kitchen ware

PTFE is best known for its use in coating non-stick

frying pan A frying pan, frypan, or skillet is a flat-bottomed pan used for frying, searing, and browning foods. It is typically in diameter with relatively low sides that flare outwards, a long handle, and no lid. Larger pans may have a small grab han ...

s and other cookware, as it is

and possesses fairly high heat resistance. The sole plates of some clothes irons are coated with PTFE.

Others

Other niche applications include: *It is often found in

ski binding A ski binding is a device that connects a ski boot to the ski. Before the 1933 invention of ski lifts, skiers went uphill and down and cross-country on the same gear. As ski lifts became more prevalent, skis—and their bindings—became increasin ...

s as a non-mechanical AFD (anti-friction device) *It can be stretched to contain small pores of varying sizes and is then placed between fabric layers to make a waterproof, breathable fabric in outdoor apparel. *It is used widely as a fabric protector to repel stains on formal school-wear, like uniform blazers. *It is frequently used as a lubricant to prevent captive insects and other

arthropods Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

from escaping. *It is used as a coating for medical and healthcare applications formulated to provide strength and heat resistance to surgical devices and other medical equipment. *It is used as a film interface patch for sports and medical applications, featuring a pressure-sensitive adhesive backing, which is installed in strategic high friction areas of footwear, insoles,

ankle-foot orthosis Orthotics ( el, Ορθός, translit=ortho, lit=to straighten, to align) is a medical specialty that focuses on the design and application of orthoses, or braces. An is "an externally applied device used to influence the structural and functio ...

, and other medical devices to prevent and relieve friction-induced blisters, calluses and foot ulceration. *Expanded PTFE membranes have been used in trials to assist

trabeculectomy Trabeculectomy is a surgical procedure used in the treatment of glaucoma to relieve intraocular pressure by removing part of the human eye, eye's trabecular meshwork and adjacent structures. It is the most common glaucoma surgery performed and all ...

surgery to treat glaucoma. *Powdered PTFE is used in

pyrotechnic composition A pyrotechnic composition is a substance or mixture of substances designed to produce an effect by heat, light, sound, gas/smoke or a combination of these, as a result of non-detonative self-sustaining exothermic reaction, exothermic chemical reac ...

s as an

oxidizer An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxid ...

with powdered metals such as

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

and

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

. Upon ignition, these mixtures form carbonaceous

soot Soot ( ) is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolysed ...

and the corresponding metal

fluoride Fluoride (). According to this source, is a possible pronunciation in British English. is an inorganic, monatomic anion of fluorine, with the chemical formula (also written ), whose salts are typically white or colorless. Fluoride salts typ ...

, and release large amounts of heat. They are used in

infrared decoy flare A flare or decoy flare is an aerial infrared countermeasure used by a plane or helicopter to counter an infrared homing ("heat-seeking") surface-to-air missile or air-to-air missile. Flares are commonly composed of a pyrotechnic composition b ...

s and as

igniter In pyrotechnics, a pyrotechnic initiator (also initiator or igniter) is a device containing a pyrotechnic composition used primarily to ignite other, more difficult-to-ignite materials, such as thermites, gas generators, and solid-fuel rockets. The ...

s for

solid-fuel rocket A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants ( fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder; they were used in warfare by the Arabs, Chinese, Persian ...

propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the e ...

s. Aluminum and PTFE is also used in some

thermobaric A thermobaric weapon, also called an aerosol bomb, a vacuum bomb or a fuel air explosive (FAE), is a type of explosive that uses oxygen from the surrounding air to generate a high-temperature explosion. The fuel–air explosive is one of the be ...

fuel compositions. *Powdered PTFE is used in a suspension with a low-viscosity, azeotropic mixture of siloxane ethers to create a lubricant for use in

twisty puzzle A combination puzzle, also known as a sequential move puzzle, is a puzzle which consists of a set of pieces which can be manipulated into different combinations by a group of operations. Many such puzzles are mechanical puzzles of polyhedral s ...

s. *In optical

radiometry Radiometry is a set of techniques for measurement, measuring electromagnetic radiation, including visible light. Radiometric techniques in optics characterize the distribution of the radiation's power (physics), power in space, as opposed to phot ...

, sheets of PTFE are used as measuring heads in spectroradiometers and broadband radiometers (e.g.,

illuminance In photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness ...

meters and UV

radiometer A radiometer or roentgenometer is a device for measuring the radiant flux (power) of electromagnetic radiation. Generally, a radiometer is an infrared radiation detector or an ultraviolet detector. Microwave radiometers operate in the microwave w ...

s) due to PTFE's capability to diffuse a transmitting light nearly perfectly. Moreover, optical properties of PTFE stay constant over a wide range of wavelengths, from UV down to near

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

. In this region, the ratio of its regular transmittance to diffuse transmittance is negligibly small, so light transmitted through a

diffuser Diffuser may refer to: Aerodynamics * Diffuser (automotive), a shaped section of a car's underbody which improves the car's aerodynamic properties * Part of a jet engine air intake, especially when operated at supersonic speeds * The channel betw ...

(PTFE sheet) radiates like

Lambert's cosine law In optics, Lambert's cosine law says that the radiant intensity or luminous intensity observed from an ideal diffusely reflecting surface or ideal diffuse radiator is directly proportional to the cosine of the angle ''θ'' between the direction ...

. Thus PTFE enables cosinusoidal angular response for a detector measuring the power of optical radiation at a surface, e.g. in solar

irradiance In radiometry, irradiance is the radiant flux ''received'' by a ''surface'' per unit area. The SI unit of irradiance is the watt per square metre (W⋅m−2). The CGS unit erg per square centimetre per second (erg⋅cm−2⋅s−1) is often used ...

measurements. *

Teflon-coated bullet Teflon-coated bullets, sometimes colloquially, also known as "cop killer bullets", are bullets that have been covered with a coating of polytetrafluoroethylene. History In the 1960s, Paul Kopsch (an Ohio coroner), Daniel Turcus (a police sergean ...

s are coated with PTFE to reduce wear on the

rifling In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the pro ...

of firearms that uncoated projectiles would cause. PTFE itself does not give a projectile an armor-piercing property. *Its high corrosion resistance makes PTFE useful in laboratory environments, where it is used for lining containers, as a coating for magnetic stirrers, and as tubing for highly corrosive chemicals such as

hydrofluoric acid Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include th ...

, which will dissolve glass containers. It is used in containers for storing

fluoroantimonic acid Fluoroantimonic acid is a mixture of hydrogen fluoride and antimony pentafluoride, containing various cations and anions (the simplest being and ). This substance is a superacid that can be over a billion times stronger than 100% pure sulfuri ...

, a

superacid In chemistry, a superacid (according to the classical definition) is an acid with an acidity greater than that of 100% pure sulfuric acid (), which has a Hammett acidity function (''H''0) of −12. According to the modern definition, a superacid ...

. *PTFE tubes are used in gas-gas heat exchangers in gas cleaning of waste incinerators. Unit power capacity is typically several megawatts. *PTFE is widely used as a

thread seal tape Thread seal tape (also known as PTFE tape, Teflon tape, or plumber's tape) is a polytetrafluoroethylene (PTFE) film tape commonly used in plumbing for sealing pipe threads. The tape is sold cut to specific widths and wound on a spool, making it ...

in plumbing applications, largely replacing paste thread dope. *PTFE membrane filters are among the most efficient industrial air filters. PTFE-coated filters are often used in

dust collection system A dust collection system is an air quality improvement system used in industrial, commercial, and home production shops to improve breathable air quality and safety by removing particulate matter from the air and environment. Dust collection syste ...

s to collect

particulate matter Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The ter ...

from air streams in applications involving high temperatures and high particulate loads such as coal-fired power plants, cement production and steel foundries. *PTFE grafts can be used to bypass

stenotic A stenosis (from Ancient Greek στενός, "narrow") is an abnormal narrowing in a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture). ''Stricture'' ...

arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pul ...

in peripheral vascular disease if a suitable autologous

vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...

graft is not available. * Many bicycle lubricants and greases contain PTFE and are used on

chains A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A c ...

and other moving parts subjected to frictional forces (such as hub bearings). * PTFE is used for some types of

dental floss Dental floss is a cord of thin filaments used in interdental cleaning to remove food and dental plaque from between teeth or places a toothbrush has difficulty reaching or is unable to reach. Its regular use as part of oral cleaning is designed t ...

. * PTFE can also be used when placing

dental fillings Dental restoration, dental fillings, or simply fillings are treatments used to restore the function, integrity, and morphology of missing tooth structure resulting from caries or external trauma as well as to the replacement of such structure sup ...

, to isolate the contacts of the adjacent tooth so the restorative materials will not stick to the adjacent tooth. * PTFE sheets are used in the production of butane hash oil due to its non-stick properties and resistance to non-polar solvents. * PTFE, associated with a slightly textured laminate, makes the plain bearing system of a

Dobsonian telescope A Dobsonian telescope is an altazimuth-mounted Newtonian telescope design popularized by John Dobson in 1965 and credited with vastly increasing the size of telescopes available to amateur astronomers. Dobson's telescopes featured a simplified ...

. * PTFE is widely used as a non-stick coating for food processing equipment; dough hoppers, mixing bowls, conveyor systems, rollers, and chutes. PTFE can also be reinforced where abrasion is present – for equipment processing seeded or grainy dough for example. *PTFE has been experimented with for

electroless nickel plating Electroless nickel-phosphorus plating is a chemical process that deposits an even layer of nickel-phosphorus alloy on the surface of a solid substrate, like metal or plastic. The process involves dipping the substrate in a water solution containi ...

. *PTFE tubing is used for Bowden tubing in

3D printers 3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer co ...

because its low friction allows the extruder stepper motor to push filament through it more easily. *PTFE is commonly used in aftermarket add-on mouse feet for

gaming mice A computer mouse (plural mice, sometimes mouses) is a hand-held pointing device that detects two-dimensional space, two-dimensional motion relative to a surface. This motion is typically translated into the motion of a pointer (user interface ...

to reduce friction of the mouse against the mouse pad, resulting in a smoother glide. *PTFE foils are commonly used with laserprinters everywhere, in their fuser unit, wrapped around the heater element(s) and as well on the opposite pressure roller to prevent any kind of sticking to it (neither the printed paper nor toner waste) *PTFE is also used to make body jewellery as it's much safer to wear compared to materials like acrylic, that release toxics into the body at 26.6°C, unlike PTFE at 650–700°C. *PTFE is used to make bookbinding tools for folding, scoring and separating sheets of paper. These are typically referred to as Teflon bone folders.

Safety

While PTFE is stable and nontoxic at lower temperatures, it begins to deteriorate at temperatures of about , it decomposes above , and

pyrolysis The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...

occurs at temperatures above . The main decomposition products are

gases and a sublimate, including

(TFE) and

difluorocarbene Difluorocarbene is the chemical compound with formula CF2. It has a short half-life, 0.5 and 20 ms, in solution and in the gas phase, respectively.Douglas A Jean Osteraas "Difluorocarbene Modification of Polymer and Fiber Surfaces," ''Journal ...

radicals (RCF2). An animal study conducted in 1955 concluded that it is unlikely that these products would be generated in amounts significant to health at temperatures below . Above those temperatures the degradation by-products can be lethal to

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

s, and can cause

flu-like symptoms Influenza-like illness (ILI), also known as flu-like syndrome or flu-like symptoms, is a medical diagnosis of possible influenza or other illness causing a set of common symptoms. These include fever, shivering, chills, malaise, dry cough, loss o ...

in humans (

polymer fume fever __NOTOC__ Polymer fume fever or fluoropolymer fever, also informally called Teflon flu, is an inhalation fever caused by the fumes released when polytetrafluoroethylene (PTFE, known under the trade name Teflon) reaches temperatures of 300 ° ...

), although in humans those symptoms disappears within a day or two of being moved to fresh air. Most cases of polymer fume fever in humans occur due to smoking PTFE-contaminated tobacco, although cases have occurred in people who have

welded Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower temperature techniques such as braz ...

near PTFE components or heated PTFE-coated cookware at for at least 4 hours. Teflon-coated cookware is unlikely to reach dangerous temperatures with normal use, as meat is usually fried between , and most

cooking oil Cooking oil is plant, animal, or synthetic liquid fat used in frying, baking, and other types of cooking. It is also used in food preparation and flavoring not involving heat, such as salad dressings and bread dips, and may be called edible oil. ...

s (except refined

safflower Safflower (''Carthamus tinctorius'') is a highly branched, herbaceous, thistle-like annual plant in the family Asteraceae. It is commercially cultivated for vegetable oil extracted from the seeds and was used by the early Spanish colonies along ...

and

avocado The avocado (''Persea americana'') is a medium-sized, evergreen tree in the laurel family (Lauraceae). It is native to the Americas and was first domesticated by Mesoamerican tribes more than 5,000 years ago. Then as now it was prized for i ...

oils) start to

smoke Smoke is a suspension of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product ...

before a temperature of is reached. A 1973 study by DuPont's Haskell Laboratory found that a 4-hour exposure to the fumes emitted by teflon cookware heated to was lethal for

parakeets A parakeet is any one of many small to medium-sized species of parrot, in multiple genera, that generally has long tail feathers. Etymology and naming The name ''parakeet'' is derived from the French wor''perroquet'' which is reflected in ...

, although that was a higher temperature than the required for fumes from pyrolyzed butter to be lethal to the birds.

Perfluorooctanoic acid Perfluorooctanoic acid (PFOA; conjugate base perfluorooctanoate; also known colloquially as C8, for its 8 carbon chain structure) is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical processes an ...

(PFOA), a chemical formerly used in the manufacture of PTFE products such as non-stick coated cookware, can be

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substan ...

ic for people who are exposed to it (see

Ecotoxicity Ecotoxicity, the subject of study in the field of ecotoxicology (a portmanteau of ecology and toxicology), refers to the biological, chemical or physical stressors that affect ecosystems. Such stressors could occur in the natural environment at ...

). Concerning levels of PFOA have been found in the blood of people who work in or live near factories where the chemical is used, and in people regularly exposed to PFOA-containing products such as some

ski wax Ski wax is a material applied to the bottom of snow runners, including skis, snowboards, and toboggans, to improve their coefficient of friction performance under varying snow conditions. The two main types of wax used on skis are glide waxes and ...

es and stain-resistant fabric coatings, but non-stick cookware was not found to be major sources of exposure as the PFOA is burned off during the manufacturing process and not present in the finished product. Non-stick coated cookware has not been manufactured using PFOA since 2013, and PFOA is no longer being made in the United States.

Ecotoxicity

Trifluoroacetate

Sodium trifluoroacetate Sodium trifluoroacetate is a chemical compound with a formula of CF3CO2Na. It is the sodium salt of trifluoroacetic acid. It is used as a source of trifluoromethylations. Basicity With a pKa of 0.23 for trifluoroacetic acid, the trifluoroaceta ...

and the similar compound chlorodifluoroacetate can both be generated when PTFE undergoes

thermolysis Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes. The reaction is usually endothermic as heat is req ...

, as well as producing longer chain polyfluoro- and/or polychlorofluoro- (C3-C14) carboxylic acids which may be equally persistent. These products can accumulate in evaporative

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

s and have been found in the roots and seeds of wetland plant species, but has not been observed to have an adverse impact on plant health or germination success.

PFOA

Perfluorooctanoic acid (PFOA, or C8) has been used as a

surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...

in the

emulsion polymerization Emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomer, and surfactant. The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer ...

of PTFE, although several manufacturers have entirely discontinued its use. PFOA persists indefinitely in the environment. PFOA has been detected in the blood of many individuals of the general US population in the low and sub-

parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...

range, and levels are higher in chemical plant employees and surrounding subpopulations. PFOA and

(PFOS) have been estimated to be in every American person’s blood stream in the parts per billion range, though those concentrations have decreased by 70% for PFOA and 84% for PFOS between 1999 and 2014, which coincides with the end of the production and phase out of PFOA and PFOS in the US. The general population has been exposed to PFOA through massive dumping of C8 waste into the ocean and near the

Ohio River The Ohio River is a long river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of Illino ...

Valley. PFOA has been detected in industrial waste, stain-resistant carpets, carpet cleaning liquids,

house dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...

, microwave popcorn bags, water, food and PTFE cookware. As a result of a class-action lawsuit and community settlement with

, three

epidemiologists Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidenc ...

conducted studies on the population surrounding a chemical plant that was exposed to PFOA at levels greater than in the general population. The studies concluded that there was an association between PFOA exposure and six health outcomes: kidney cancer, testicular cancer,

ulcerative colitis Ulcerative colitis (UC) is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary symptoms of active disease are abdominal pain and diarrhea mixed with blood (hematochezia). Weight loss, fever, and a ...

, thyroid disease,

hypercholesterolemia Hypercholesterolemia, also called high cholesterol, is the presence of high levels of cholesterol in the blood. It is a form of hyperlipidemia (high levels of lipids in the blood), hyperlipoproteinemia (high levels of lipoproteins in the blood), ...

(high cholesterol), and pregnancy-induced hypertension. Overall, PTFE cookware is considered a minor exposure pathway to PFOA.

GenX

As a result of the lawsuits concerning the PFOA class-action lawsuit, DuPont began to use GenX, a similarly fluorinated compound, as a replacement for perfluorooctanoic acid in the manufacture of

s, such as Teflon-brand PTFE. However, in lab tests on rats, GenX has been shown to cause many of the same health problems as PFOA. The chemicals are manufactured by

, a corporate spin-off of DuPont, in

Fayetteville, North Carolina Fayetteville () is a city in and the county seat of Cumberland County, North Carolina, United States. It is best known as the home of Fort Bragg, a major U.S. Army installation northwest of the city. Fayetteville has received the All-America C ...

. While PFOA was phased out by 2014, Chemours was already found to be dumping GenX into the

Cape Fear River The Cape Fear River is a long blackwater river in east central North Carolina. It flows into the Atlantic Ocean near Cape Fear, from which it takes its name. The river is formed at the confluence of the Haw River and the Deep River (North Carol ...

in 2017, with the

North Carolina Department of Environmental Quality The North Carolina Department of Environmental Quality (NCDEQ) is an agency of the government of North Carolina that focuses on the preservation and protection of natural resources and public health. The Department is headed by the Secretary of E ...

(NCDEQ) ordering Chemours to halt discharges of all fluorinated compounds on September 5, 2017.

Similar polymers

The Teflon trade name is also used for other polymers with similar compositions: *

Perfluoroalkoxy alkane Perfluoroalkoxy alkanes (PFA) are fluoropolymers. They are copolymers of tetrafluoroethylene (C2F4) and perfluoroethers (C2F3ORf, where Rf is a perfluorinated group such as trifluoromethyl (CF3)). The properties of these polymers are similar ...

(PFA) *

Fluorinated ethylene propylene Fluorinated ethylene propylene (FEP) is a copolymer of hexafluoropropylene and tetrafluoroethylene. It differs from the polytetrafluoroethylene (PTFE) resins in that it is melt-processable using conventional injection molding and screw extrusion ...

(FEP) These retain the useful PTFE properties of low friction and nonreactivity, but are also more easily formable. For example, FEP is softer than PTFE and melts at ; it is also highly transparent and resistant to sunlight.FEP Detailed Properties
Parker-TexLoc, 13 April 2006. Retrieved 10 September 2006.

Notes

References

External links

Plasma Processes and Adhesive Bonding of Polytetrafluoroethylene

PTFE (polytetrafluoroethylene) (Properties) , Fluorotherm.com
{{DEFAULTSORT:Polytetrafluoroethylene American inventions Biomaterials Dielectrics Dry lubricants DuPont DuPont products Fluorocarbons Fluoropolymers Plastics Pyrotechnic oxidizers Roofing materials Engineering plastic