ECTFE (ethylene-chlorotrifluoroethylene) is an

alternating copolymer In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are som ...

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 bond, carbon–carbon doub ...

and

chlorotrifluoroethylene Chlorotrifluoroethylene (CTFE) is a chlorofluorocarbon with chemical formula CFCl=CF2. It is commonly used as a refrigerant in cryogenic applications. CTFE has a carbon-carbon double bond and so can be polymerized to form polychlorotrifluoroethy ...

. It is a

semi-crystalline Crystallinity refers to the degree of structural order in a solid. In a crystal, the atoms or molecules are arranged in a regular, periodic manner. The degree of crystallinity has a large influence on hardness, density, transparency and diffusi ...

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, ...

(a partly fluorinated

polymer A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their br ...

), with chemical corrosion resistance properties.

Physical and chemical properties

ECTFE (ethylene chlorotrifluoroethylene) is a polymer known for its chemical resistance, making it suitable for various industrial applications. It is resistant to acids at high concentrations/temperatures, caustic media,

oxidizing agents 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 ''electron donor''). In ot ...

, and many

solvents A solvent (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for p ...

, similar to

PTFE Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off fro ...

(polytetrafluoroethylene). One of the key properties of ECTFE is its

permeation In physics and engineering, permeation (also called imbuing) is the penetration of a wikt:permeate#English, permeate (a fluid such as a liquid, gas, or vapor) through a solid. It is directly related to the concentration gradient of the permeate, ...

resistance to large molecules, which is generally slow and not significant in practical applications. Small molecules, however, may permeate through the polymer matrix. In lining or coating applications using ECTFE, permeability of certain small molecules determines the lifetime of anti-corrosion protection. Small molecules such as 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, and CH₃OH are relatively mobile in the polymer matrix and lead to measurable effects. This permeation resistance is particularly critical in lining and coating applications, where the material is used to protect underlying 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-fibre ...

(FRP) or

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

, from corrosive substances. The polymer's resistance to permeation is attributed to the presence of chlorine atoms in the polymer chain, which occupies free volume and restricts the movement of small molecules through the material. ECTFE finds applications in various industries due to its favorable chemical resistance properties, providing durable and reliable protection in harsh environments. ECTFE has a continuous usage temperature range between –76°C and +150°C (–105°F to +300°F). It has strong

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 (or the Young modulus) is a mechanical property of solid materials that measures the tensile or compressive stiffness when the force is applied lengthwise. It is the modulus of elasticity for tension or axial compression. Youn ...

in the range of 1700

MPa MPA or mPa may refer to: Academia Academic degrees * Master of Performing Arts * Master of Professional Accountancy * Master of Public Administration * Master of Public Affairs Schools * Mesa Preparatory Academy * Morgan Park Academy * M ...

, allowing for self-standing items and pressure piping systems. The polymer maintains high impact strength in

cryogenic In physics, cryogenics is the production and behaviour of materials at very low temperatures. The 13th International Institute of Refrigeration's (IIR) International Congress of Refrigeration (held in Washington, DC in 1971) endorsed a univers ...

applications. In terms of fire resistance, ECTFE shows a

limiting oxygen index The limiting oxygen index (LOI) is the minimum concentration of oxygen, expressed as a percentage, that will support combustion of a polymer. It is measured by passing a mixture of oxygen and nitrogen over a burning specimen, and reducing the oxygen ...

of 52%. This value places it 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. Its chemical formula is (C2H2F2)''n''. PVDF is a specialty plastic used ...

with a limiting oxygen index of 44% or

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 i ...

with a limiting oxygen index of 30%. ECTFE acts as 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 electrical conductor, conductors—con ...

, with high

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

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 insul ...

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. ECTFE has good

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

(UV) resistance, in particular against

UV-A Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the ...

and UV-B. Films made of the polymer can be transparent.

Applications

ECTFE is applied in several ways: * By electrostatic powder coating on metal surfaces * By rotolining on metal surfaces rotolining grade Halar 6012F * 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 comp ...

s, etc.) * 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 the material. It is then slowly rotated (usually around two perpendicular axes), causing the softened material to disperse and stick to ...

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. Such 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 into vessels, pipes or valves is done in the chemical industry. Thick sheets are compression molded and can be manufactured 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 for corrosion protection, for which it is used in industries including: * Bleaching towers in pulp and paper *

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

production and storage * Flue gas treatment in particular in the SNOX and WSA processes *

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

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

Halogen The halogens () are a group in the periodic table consisting of six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and the radioactive elements astatine (At) and tennessine (Ts), though some authors would ...

-related industry (

bromine Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between th ...

chlorine Chlorine is a chemical element; it has Symbol (chemistry), 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 ...

fluorine Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...

) * Acid handling (

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

nitric acid Nitric acid is an inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into nitrogen oxide, oxides of nitrogen. Most com ...

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, ...

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, astatine, or ...

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. Swedish chemist ...

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

heap leaching 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. It is also used in the pharmaceutical industry. 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. It is also used for braiding in that field. ECTFE in the form of a monofilament fiber is used in flue gas treatment and in certain chemical processes. Unlike PTFE, ECTFE can be crimped, which allows its production in the form of nonwoven fibers with high

surface area The surface area (symbol ''A'') 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 d ...

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 compared to PTFE. ECTFE is used for manufacturing gaskets to store

liquid oxygen Liquid oxygen, sometimes abbreviated as LOX or LOXygen, is a clear cyan liquid form of dioxygen . It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an application which is ongoing. Physical ...

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 another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicle ...

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 astron ...

applications.

References

{{reflist Plastics Fluoropolymers Copolymers Thermoplastics

Physical and chemical properties

Applications

See also

References