Polyether ether ketone

---

title: "Polyether ether ketone" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["polyethers", "organic-polymers", "thermoplastics", "fused-filament-fabrication"] description: "Semicrystalline thermoplastic with high mechanical and chemical resistance" topic_path: "science/chemistry" source: "https://en.wikipedia.org/wiki/Polyether_ether_ketone" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Semicrystalline thermoplastic with high mechanical and chemical resistance ::

::data[format=table title="Infobox material"]

Field	Value
name	Polyether ether ketone
density	1320 kg/m3
water_absorption_24h	0.1%
youngs_modulus	3.6 GPa
tensile_strength	90–100 MPa
elongation	50%
notch_test	55 kJ/m2
melting_point	343 °C
glass_transition	143 °C
thermal_conductivity	0.25 W/(m⋅K)
footnotes
::

| Name = Polyether ether ketone | ImageFile = Polyetherketon.svg | ImageClass = skin-invert | Section1 = {{ Chembox Identifiers | PubChem = 19864017 | CASNo = 31694-16-3 | Section2 = {{Chembox Properties | Formula = (C19H12O3)n | MolarMass = 288.3 g/mol | Density = 1320 kg/m3 | MeltingPtC = 343 | Section9 = {{Chembox Related | OtherCompounds = |name=Polyether ether ketone |density=1320 kg/m3 |water_absorption_24h=0.1% |youngs_modulus=3.6 GPa |tensile_strength=90–100 MPa |elongation=50% |notch_test=55 kJ/m2 |melting_point=343 °C |glass_transition=143 °C |thermal_conductivity=0.25 W/(m⋅K) |footnotes= Polyether ether ketone (PEEK) is a beige coloured organic thermoplastic polymer in the polyaryletherketone (PAEK) family, used in engineering applications. It was invented in November 1978 and brought to market in the early 1980s by part of Imperial Chemical Industries (ICI), the PEEK division was acquired through a management buyout, giving rise to Victrex PLC.

Synthesis

PEEK polymers are obtained by step-growth polymerization by the dialkylation of bisphenolate salts. Typical is the reaction of 4,4'-difluorobenzophenone with the disodium salt of hydroquinone, which is generated in situ by deprotonation with sodium carbonate. The reaction is conducted around 300 °C in polar aprotic solvents - such as diphenyl sulfone.

::figure[src="https://upload.wikimedia.org/wikipedia/commons/f/fd/Synthesis_of_PEEK.svg"] ::

Properties

PEEK is a semicrystalline thermoplastic with excellent mechanical and chemical resistance properties that are retained to high temperatures. The processing conditions used to mould PEEK can influence the crystallinity and hence the mechanical properties. Its Young's modulus is 3.6 GPa and its tensile strength is 90 to 100 MPa. PEEK has a glass transition temperature of around 143 °C (289 °F) and melts around 343 °C (662 °F). Some grades have a useful operating temperature of up to 250 °C (482 °F). The thermal conductivity increases nearly linearly with temperature between room temperature and solidus temperature. It is highly resistant to thermal degradation, as well as to attack by both organic and aqueous environments. It is attacked by halogens and strong Brønsted and Lewis acids, as well as some halogenated compounds and aliphatic hydrocarbons at high temperatures. It is soluble in concentrated sulfuric acid at room temperature, although dissolution can take a very long time unless the polymer is in a form with a high surface-area-to-volume ratio, such as a fine powder or thin film. It has high resistance to biodegradation.

Applications

PEEK is used to fabricate items for demanding applications, including bearings, piston parts, pumps, high-performance liquid chromatography columns, compressor plate valves, and electrical cable insulation. It is one of the few plastics compatible with ultra-high vacuum applications, which makes it suitable for aerospace, automotive, and chemical industries. PEEK is used in medical implants, for example in creating a partial replacement skull in neurosurgical applications.

PEEK is used in spinal fusion devices and reinforcing rods. It is radiolucent, but it is hydrophobic causing it to not fully fuse with bone. PEEK seals and manifolds are commonly used in fluid applications. PEEK also performs well in high temperature applications (up to 260 °C/500 °F). Because of this and its low thermal conductivity, it is also used in fused filament fabrication (FFF) printing to thermally separate the hot end from the cold end.

Processing options

::figure[src="https://upload.wikimedia.org/wikipedia/commons/2/22/MELT_3D_printer_ESA401434.jpg" caption="ESA]]'s ''Manufacturing of Experimental Layer Technology'' (MELT) 3D printer can print polyether ether ketone (PEEK)"] ::

PEEK melts at a relatively high temperature (343 °C / 649.4 °F) compared to most other thermoplastics. In the range of its melting temperature it can be processed using injection moulding or extrusion methods. It is technically feasible to process granular PEEK into filament form and 3D printing parts from the filament material using fused deposition modeling – FDM (or fused filament fabrication – FFF) technology. PEEK filaments have been demonstrated for producing medical devices up to class IIa. With this new filament, it is possible to use the FFF method for different medical applications like dentures.

In its solid state PEEK is readily machinable, for example, by CNC milling machines and is commonly used to produce high-quality plastic parts that are thermostable and both electrically and thermally insulating. Filled grades of PEEK can also be CNC machined, but special care must be taken to properly manage stresses in the material.

PEEK is a high-performance polymer, but its high price, due to its complex production process, restricts its use to only the most demanding applications.

Shape-memory PEEK in biomechanical applications

PEEK is not traditionally a shape-memory polymer; however, recent advances in processing have allowed shape-memory behaviour in PEEK with mechanical activation. This technology has expanded to applications in orthopaedic surgery.

References

References

1. (2003). "Polymeren, van keten tot kunstof". DUP Blue.
2. "Victrex celebrates 40 years of PEEK success".
3. "Why PEEK?".
4. Kemmish, David. (2010). "Update on the Technology and Applications of PolyArylEtherKetones". ISmithers.
5. [http://www.makeitfrom.com/material-data/?for=Polyetheretherketone-PEEK Material Properties Data: Polyetheretherketone (PEEK)], www.makeitfrom.com.
6. David Parker. (15 April 2012). "Polymers, High-Temperature".
7. (2008). "Influence of the CNT content on the thermophysical properties of PEEK-CNT composites".
8. (May 2010). "Mechanism of thermal decomposition of poly(ether ether ketone) (PEEK) from a review of decomposition studies". Polymer Degradation and Stability.
9. "PEEK (Polyether Ether Ketone)".
10. Lauzon, Michael. (May 4, 2012). "Diversified Plastics Inc., PEEK playing role in space probe". [[Crain Communications Inc]].
11. (2020-02-01). "10 Porous TLIF cages to Know...!".
12. "Properties of PEEK Material".
13. (24 March 2014). "Arevo Labs announces Carbon Fiber and Nanotube-reinforced High Performance materials for 3D Printing Process". LouVan Communications Inc..
14. "3D Printing High-Strength Carbon Composites Using PEEK, PAEK". Design News.
15. [http://www.indmatec.com/press/peek-filament-medtec Press release Indmatec PEEK MedTec]{{Dead link. (December 2024)
16. (2008). "Synthesis of poly(ether ether ketone) assisted by microwave irradiation and its characterization". Polymer Bulletin.
17. Anonymous. "Surgical Technologies; MedShape Solutions, Inc. Announces First FDA-cleared Shape Memory PEEK Device; Closing of $10M Equity Offering". Medical Letter on the CDC & FDA.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::