- This article is about the resin. For the BASIC programming language function, see PEEK and POKE.
Polyetheretherketones, also referred to as polyketones, are 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.
PEEK is partially crystalline, and has a glass transition temperature of 143 °C and a melting temperature of 334 °C. The material is resistant to both organic and aqueous environments, and are used in bearings, piston parts, pumps, compressor plate valves, and cable insulation applications.