PEEK is a semi crystalline thermoplastic with excellent mechanical and chemical resistance properties that are retained to high temperatures. The processing conditions used to mold PEEK can influence the crystallinity, and hence the mechanical properties. The Young’s modulus is 3.6 GPa and its tensile strength 90 to 100 MPa.
Some grades have a useful operating temperature of up to 482°F for long term service. The thermal conductivity increases nearly linearly versus temperature between room temperature and solidus temperature. It is highly resistant to thermal degradation as well as attack by both organic and aqueous environments. It is attacked by halogens and strong Bronsted and Lewis acids as well as some halogenated compounds and aliphatic hydrocarbons at high temperatures. It dissolves completely in concentrated sulfuric acid at room temperature.
Because of its robustness, PEEK is used to fabricate items used in demanding applications, including bearings, piston parts, pumps, HPLC columns, compressor plate valves, and cable insulation. It is one of the few plastics compatible with ultra-high vacuum applications. PEEK is considered an advanced biomaterial used in medical implants. It is finding increase use in spinal fusion devices and reinforcing rods. It is extensively used in the aerospace, automotive, and chemical process industries.
