ECTFE (ethylenechlorotrifluoroethylene) is a copolymer of

ethylene Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds). Ethylene ...

and chlorotrifluoroethylene. It is a semi-crystalline

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 "Tefl ...

(a partially fluorinated

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 ...

) designed to provide chemical resistance in heavy-duty corrosion applications.

Physical and chemical properties

ECTFE is resistant to acids at high concentrations and temperatures, caustic media,

oxidizing agent 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 oxi ...

s and many solvents. It is said to have similar chemical resistance to

PTFE Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chem ...

. A chemical resistance table, based on immersion tests, has explored this further. Permeation of large molecules is slow in fluoropolymers and thus is not relevant in the final application. Small molecules, however, may permeate through the polymer matrix at a relevant time. In lining or coating applications, the permeation of certain small molecules determines the lifetime of anti-corrosion protection. H₂O, O₂, Cl₂, H₂S,

HCl HCL may refer to: Science and medicine * Hairy cell leukemia, an uncommon and slowly progressing B cell leukemia * Harvard Cyclotron Laboratory, from 1961 to 2002, a proton accelerator used for research and development * Hollow-cathode lamp, a s ...

, HF, HBr, N₂, H₂, CH₃OH, etc. are relatively mobile in a polymer matrix and lead to measurable effects. Permeation resistance is significant for lining and coating applications, because permeating species may attack underlying mechanical layers, such as

fiber reinforced plastic Fibre-reinforced plastic (FRP; also called fibre-reinforced polymer, or in American English ''fiber'') is a composite material made of a polymer matrix reinforced with fibres. The fibres are usually glass (in fibreglass), carbon (in carbon-fibr ...

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistan ...

. This high permeation resistance to small molecules is a consequence of the free volume occupied by the

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

atom in the polymer chain. ECTFE has a continuous usage temperature range between typically –76 °C and +150 °C (–105F to +300F). It has good

impact resistance In materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing.Young's modulus Young's modulus E, the Young modulus, or the modulus of elasticity in tension or compression (i.e., negative tension), is a mechanical property that measures the tensile or compressive stiffness of a solid material when the force is applied ...

in the range of 1700 MPa, allowing for self-standing items and pressure piping systems. ECTFE maintains high impact strength in

cryogenic In physics, cryogenics is the production and behaviour of materials at very low temperatures. The 13th IIR International Congress of Refrigeration (held in Washington DC in 1971) endorsed a universal definition of “cryogenics” and “cr ...

applications. In terms of fire resistance, ECTFE shows a limiting oxygen index of 52%. This is between the fully fluorinated polymers

, PFA and FEP with a limiting oxygen index of 95% and other partially fluorinated polymers like

PVDF Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. PVDF is a specialty plastic used in applications requiring the highest pu ...

with a limiting oxygen index of 44% and

ETFE Ethylene tetrafluoroethylene (ETFE) is a fluorine-based plastic. It was designed to have high corrosion resistance and strength over a wide temperature range. ETFE is a polymer and its source-based name is poly(ethene-co-tetrafluoroethene). It is ...

with a limiting oxygen index of 30%. ECTFE is an

electrical insulator An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current ...

, with high

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 ...

and a low

dielectric constant The relative permittivity (in older texts, dielectric constant) is the permittivity of a material expressed as a ratio with the electric permittivity of a vacuum. A dielectric is an insulating material, and the dielectric constant of an insula ...

as well as a low

dissipation factor In physics, the dissipation factor (DF) is a measure of loss-rate of energy of a mode of oscillation (mechanical, electrical, or electromechanical) in a dissipative system. It is the reciprocal of quality factor, which represents the "quality" or ...

, allowing its use for wire and cable primary and secondary jacketing. Similar to other fluoropolymers, ECTFE has good UV resistance, in particular against UV-A and

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

. ECTFE films can be transparent. ECTFE is welded in a variety of methods, including : * Butt welding * Infrared welding * High frequency welding *

Hot gas welding Hot-gas welding is a manual plastic welding process for joining thermoplastic materials. A hot-gas torch is used to direct hot air to both the joint surface and weld rod, heating the materials to their softening temperature. Application of pressure ...

* Ultrasonic welding

Applications

ECTFE is applied in several ways: * By electrostatic powder coating on metal surfaces * By rotolining on metal surfaces rotolining grade Halar 6012Fhttp://catalog.ides.com/Datasheet.aspx?I=92041&FMT=PDF&E=158590 * By sheet lining on metal surface or on

FRP (

glass fiber Glass fiber ( or glass fibre) is a material consisting of numerous extremely fine fibers of glass. Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the inventio ...

carbon fiber Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...

, ...). * By extrusion or injection molding of self standing items, in particular pressure pipes * By

rotomolding Rotational molding (BrE: moulding) involves a heated mold which is filled with a charge or shot weight of material. It is then slowly rotated (usually around two perpendicular axes), causing the softened material to disperse and stick to the ...

of self standing items like tanks or other shapes (rotomolding grade) * As a protective film using an adequate adhesive ECTFE powder is most commonly used in electrostatic powder coating. ECTFE powder coatings have a typical thickness of 0,8 mm but can be applied up to 2 mm with a special grade for high build up. Extrusion of ECTFE fabric-backed sheets and subsequent fabrication to vessels, pipes or valves is used in the chemical industry. Thick sheets are compression molded and can go up to 50 mm in thickness. They are used in the semiconductor industry for wet benches or machining other parts. The most common application of ECTFE is in the field of corrosion protection. ECTFE is used for corrosion protection in industries including: * Bleaching towers in pulp and paper *

Sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...

production and storage *

Flue gas Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced a ...

treatment in particular in the SNOX and WSA process *

Electrolysis In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from n ...

collectors or drying towers in the chlorine industry * Transport vessels for hazardous goods, in particular class 8 *

Halogen The halogens () are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). In the modern IUPAC nomenclature, this group is ...

related industry (

Bromine Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table (halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a simila ...

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 ...

) * Acid handling (

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...

nitric acid Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...

hydrogen halide In chemistry, hydrogen halides (hydrohalic acids when in the aqueous phase) are diatomic, inorganic compounds that function as Arrhenius acids. The formula is HX where X is one of the halogens: fluorine, chlorine, bromine, iodine, or astatine. A ...

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The unde ...

, etc.) * Mining applications, in particular high pressure

heap leach Heap leaching is an industrial mining process used to extract precious metals, copper, uranium, and other compounds from ore using a series of chemical reactions that absorb specific minerals and re-separate them after their division from other e ...

ECTFE has been widely used in the semiconductor industry, for wet tool and tubing systems for lithographic chemicals. ECTFE is also used in the pharmaceutical industry. Moreover, ECTFE is used for primary and secondary jacketing in specialty cables like data cables or self-regulating heating cables, applications where good fire resistance and electrical properties are key properties. ECTFE is also used for braiding in that field. ECTFE in the form of a monofilament fiber is used in flue gas treatment and in certein chemical processes. Unlike

, ECTFE can be crimped which allows its production in the form of nonwoven fibers with high

surface area The surface area of a solid object is a measure of the total area that the surface of the object occupies. The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of arc ...

and

porosity Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...

. Even though such material has low chemical reactivity, ECTFE in general has somewhat lower chemical resistance comparing to PTFE. Halar films are used in the

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

industry as well as for

photovoltaic Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially us ...

front and back sheets. ECTFE is used for manufacturing gaskets to store

liquid oxygen Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an applica ...

and other

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 for

aerospace Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace engineering consists of aeronautics and astrona ...

applications.{{Cite web , date=2014-10-01 , title=Understanding ECTFE Industrial Coatings , url=https://toefco.com/understanding-ectfe-coatings/ , access-date=2022-07-11 , website=Toefco , language=en-US

References

Plastics Fluoropolymers Copolymers Thermoplastics

Physical and chemical properties

Applications

See also

References