Polyetheretherketones (PEEK), also referred to as polyketones, are composite materials obtained from aromatic dihalides and bisphenolate salts by nucleophilic substitution. The bisphenolate salt is formed in situ from bisphenol and either added sodium or added alkali metal carbonate or hydroxide. In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... Kilogram per cubic metre is the SI measure of density and is represented as kg/m³, where kg stands for kilogram and m³ stands for cubic metre. ... In solid mechanics, Youngs modulus (E) is a measure of the stiffness of a given material. ... mega- (symbol M) is an SI prefix in the SI system of units denoting a factor of 106, i. ... The pascal (symbol: Pa) is the SI derived unit of pressure or stress (also: Youngs modulus and tensile strength). ... Tensile strength isthe measures the force required to pull something such as rope, wire, or a structural beam to the point where it breaks. ... mega- (symbol M) is an SI prefix in the SI system of units denoting a factor of 106, i. ... The pascal (symbol: Pa) is the SI derived unit of pressure or stress (also: Youngs modulus and tensile strength). ... Kilo (symbol: k) is a prefix in the SI system denoting 103 or 1000. ... The joule (IPA pronunciation: or ) (symbol: J) is the SI unit of energy. ... The metre (American English:meter) is a measure of length. ... A material’s glass transition temperature, Tg, is the temperature below which molecules have little relative mobility. ... The degree Celsius (symbol: °C) is an SI derived unit of temperature. ... The degree Celsius (symbol: °C) is an SI derived unit of temperature. ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The degree Celsius (symbol: °C) is an SI derived unit of temperature. ... The metre (American English:meter) is a measure of length. ... The kelvin (symbol: K) is a unit increment of temperature and is one of the seven SI base units. ... During heat transfer, the energy that is stored in the intermolecular bonds between atoms changes. ... The kelvin (symbol: K) is a unit increment of temperature and is one of the seven SI base units. ... Specific heat capacity, also known simply as specific heat (Symbol: C or c) is the measure of the heat energy required to raise the temperature of a given amount of a substance by one degree. ... Kilo (symbol: k) is a prefix in the SI system denoting 103 or 1000. ... The joule (symbol J, also called newton metre, or coulomb volt) is the SI unit of energy and work. ... The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. It was assigned to the United States in 1889 and is periodically recertified and traceable to the primary international standard, The Kilogram, held at the Bureau International des Poids et... The kelvin (symbol: K) is a unit increment of temperature and is one of the seven SI base units. ... The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. It was assigned to the United States in 1889 and is periodically recertified and traceable to the primary international standard, The Kilogram, held at the Bureau International des Poids et... Look up peek, Peek, PEEK in Wiktionary, the free dictionary. ... Polyketones are a family of high-performance thermoplastic polymers. ... Composite materials (or composites for short) are engineering materials made from two or more components. ... In chemistry, nucleophilic substitution is a class of substitution reaction in which an electron-rich nucleophile attacks a molecule and replaces a group or atom, called the leaving group. ...

Image File history File links Polyetheretherketone (PEEK) synthesis and structure. ...

PEEK is a thermoplastic with extraordinary mechanical properties. The Young's modulus is 3.6 GPa (522,000 psi) and its tensile strength 170 MPa (25,000 psi). A thermoplastic is a material that is plastic or deformable, melts to a liquid when heated and freezes to a brittle, glassy state when cooled sufficiently. ... In solid mechanics, Youngs modulus (E) is a measure of the stiffness of a given material. ...

PEEK is partially crystalline, and is highly unusual in exhibiting two glass transition temperatures at around 140°C (284°F) and around 275ºC (527°F), depending on cure cycle and precise formulation. PEEK melts at around 350°C (662°F) and is highly resistant to thermal degradation. The material is also resistant to both organic and aqueous environments, and is used in bearings, piston parts, pumps, compressor plate valves, and cable insulation applications. It is one of the few plastics compatible with ultra-high vacuum applications. A material’s glass transition temperature, Tg, is the temperature below which molecules have little relative mobility. ... Ultra high vacuum (UHV) is the regime of characterised by pressures lower than about 10-7 Pascal or 100 nanopascals (~10-9 torr). ...

PEEK is considered an advanced biomaterial used in medical implants, often in reinforced format using biocompatible fibre fillers such as carbon. Also in carbon fibre reinforced form, PEEK has come under consideration as an aerospace structural material due to its high strength-to-weight ratio. Electronic circuitry also has a high demand for PEEK's large temperature range.

Chemical resistance

PEEK also exhibits good chemical resistance in many environments, including alkalis (i.e. sodium, potassium and ammonium hydroxides), aromatic hydrocarbons, alcohols (i.e. ethanol, propanol), greases, oils and halogenated hydrocarbons. In chemistry, an alkali (from Arabic: al-qalyالقلوي, القالي ) is a basic, ionic salt of an alkali metal or alkali earth metal element. ...

However, its performance in acids is very dependent on the type of acid - PEEK shows poor resistance in concentrated sulfuric, nitric, hydrochloric, hydrobromic and other mineral acids (though performance may be adequate for short term use with these acids in very dilute form). Its resistance to hydrofluoric acid and oleum is very poor. PEEK shows good resistance to phosphoric acid and organic acids (acetic, citric, oxalic, tartaric etc.), but varying resistance in the presence of halogens. PEEK is resistant to dissolution by some aldehydes and ketones such as acetone, but not (at higher temperature) methylethyl ketone. Sulfuric (or sulphuric) acid, H2SO4, is a strong mineral acid. ... The chemical compound nitric acid (HNO3), also known as aqua fortis and spirit of nitre, is an aqueous solution of hydrogen nitrate (anhydrous nitric acid). ... The chemical compound hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride gas (HCl). ... It has been suggested that this article or section be merged into hydrogen bromide. ... Hydrofluoric acid is a solution of hydrogen fluoride in water. ... Oleum refers to a solution of sulfur trioxide in sulfuric acid or sometimes more specifically to pyrosulfuric acid, disulfuric acid. ... Phosphoric acid, also known as orthophosphoric acid or phosphoric(V) acid, is an inorganic mineral acid having the chemical formula H3PO4. ...

References

1. ^ A.K. vam der Vegt & L.E. Govaert, Polymeren, van keten tot kunstof, ISBN 90-407-2388-5

External links

• PEEK Material Data Sheets

• PEEK chemical structure and numeric properties

• PEEK Overview & Product Image