Polyether ether ketone
| |
| Identifiers | |
|---|---|
PubChemCID
|
|
| Properties | |
| (C19H12O3)n | |
| Molar mass | 288.3 g/mol |
| Density | 1.32 g/cm3 |
| Melting point | 343 °C (649 °F; 616 K) |
| Related compounds | |
Related compounds
|
|
Except where otherwise noted, data are given for materials in theirstandard state(at 25 °C [77 °F], 100 kPa).
| |
| Polyether ether ketone | |
|---|---|
| Physical properties | |
| Density(ρ) | 1.32 g/cm3 |
| Water absorption—over 24 hours | 0.1% |
| Mechanical properties | |
| Young's modulus(E) | 3.6GPa |
| Tensile strength(σt) | 90–100MPa |
| Elongation(ε)atbreak | 50% |
| Notch test | 55 kJ/m2 |
| Thermal properties | |
| Melting temperature(Tm) | 343 °C |
| Glass transition temperature(Tg) | 143 °C |
| Thermal conductivity(k) | 0.25W/(m⋅K) |
| [1] | |
Polyether ether ketone(PEEK) is a colourlessorganicthermoplasticpolymerin thepolyaryletherketone(PAEK) family, used in engineering applications. It was invented in November 1978[2]and brought to market in the early 1980s by part ofImperial Chemical Industries (ICI)that later becameVictrex PLC.[3]
Synthesis
[edit]PEEK polymers are obtained bystep-growth polymerizationby the dialkylationof bisphenolatesalts. Typical is the reaction of4,4'-difluorobenzophenonewith the disodium salt ofhydroquinone,which is generated in situ bydeprotonationwithsodium carbonate.The reaction is conducted around 300 °C in polaraproticsolvents - such asdiphenyl sulfone.[4][5]
Properties
[edit]PEEK is a semicrystallinethermoplasticwith 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. ItsYoung's modulusis 3.6 GPa and its tensile strength is 90 to 100 MPa.[6]PEEK has aglass transition temperatureof 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).[4]The thermal conductivity increases nearly linearly with temperature between room temperature andsolidustemperature.[7]It is highly resistant tothermal degradation,[8]as well as to attack by both organic and aqueous environments. It is attacked by halogens and strongBrønstedandLewis 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
[edit]PEEK is used to fabricate items for demanding applications, includingbearings,pistonparts,pumps,high-performance liquid chromatographycolumns, compressor platevalves,andelectrical cableinsulation.It is one of the few plastics compatible withultra-high vacuumapplications, which makes it suitable for aerospace, automotive, and chemical industries.[9]PEEK is used inmedical implants,for example in creating a partial replacement skull in neurosurgical applications.
PEEK is used inspinal fusiondevices and reinforcing rods.[10]It isradiolucent,but it is hydrophobic causing it to not fully fuse with bone.[9][11]PEEK seals and manifolds are commonly used in fluid applications. PEEK also performs well in high temperature applications (up to 260 °C/500 °F).[12]Because of this and its low thermal conductivity, it is also used infused filament fabrication(FFF) printing to thermally separate the hot end from the cold end.
Processing options
[edit]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 usinginjection mouldingorextrusionmethods. It is technically feasible to process granular PEEK into filament form and 3D printing parts from the filament material usingfused deposition modeling– FDM (or fused filament fabrication – FFF) technology.[13][14]PEEK filaments have been demonstrated for producing medical devices up to classIIa.[15]With this new filament, it is possible to use the FFF method for different medical applications likedentures.
In its solid state PEEK is readily machinable, for example, byCNCmilling machinesand 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 ahigh-performance polymer,but its high price, due to its complex production process, restricts its use to only the most demanding applications.[16]
Shape-memory PEEK in biomechanical applications
[edit]PEEK is not traditionally ashape-memory polymer;however, recent advances in processing have allowed shape-memory behaviour in PEEK with mechanical activation. This technology has expanded to applications inorthopaedic surgery.[17]
References
[edit]- ^van der Vegt, A.K.; Govaert, L.E. (2003).Polymeren, van keten tot kunstof(in Dutch) (5th ed.). DUP Blue.ISBN90-407-2388-5.
- ^"Victrex celebrates 40 years of PEEK success".Victrex.Retrieved2021-11-01.
- ^"Why PEEK?".drakeplastics.com.Retrieved23 April2018.
- ^abDavid Parker; Jan Bussink; Hendrik T. van de Grampe; Gary W. Wheatley; Ernst-Ulrich Dorf; Edgar Ostlinning; Klaus Reinking (15 April 2012).Polymers, High-Temperature.Ullmann's Encyclopedia of Industrial Chemistry.doi:10.1002/14356007.a21_449.pub3.ISBN978-3527306732.(subscription required)
- ^Kemmish, David (2010).Update on the Technology and Applications of PolyArylEtherKetones.ISmithers.ISBN978-1-84735-408-2.
- ^Material Properties Data: Polyetheretherketone (PEEK),www.makeitfrom.com.
- ^Blumm, J.; Lindemann, A.; Schopper, A. (2008). "Influence of the CNT content on the thermophysical properties of PEEK-CNT composites".Proceedings of the 29th Japan Symposium on Thermophysical Properties, October 8–10, 2008, Tokyo.pp. 306–8.ISSN0911-1743.
- ^Patel, Parina; Hull, T. Richard; McCabe, Richard W.; Flath, Dianne; Grasmeder, John; Percy, Mike (May 2010)."Mechanism of thermal decomposition of poly(ether ether ketone) (PEEK) from a review of decomposition studies"(PDF).Polymer Degradation and Stability.95(5): 709–718.doi:10.1016/j.polymdegradstab.2010.01.024.
- ^ab"PEEK (Polyether Ether Ketone)".www.scientificspine.com.Retrieved2020-05-06.
- ^Lauzon, Michael (May 4, 2012)."Diversified Plastics Inc., PEEK playing role in space probe".PlasticsNews.com.Crain Communications Inc.RetrievedMay 6,2012.
- ^"10 Porous TLIF cages to Know...!".SPINEMarketGroup.2020-02-01.Retrieved2020-05-06.
- ^"Properties of PEEK Material".www.uplandfab.com.
- ^Newsom, Michael (24 March 2014)."Arevo Labs announces Carbon Fiber and Nanotube-reinforced High Performance materials for 3D Printing Process".Solvay Press Releases.LouVan Communications Inc.Retrieved27 January2016.
- ^Thryft, Ann."3D Printing High-Strength Carbon Composites Using PEEK, PAEK".Design News.Retrieved27 January2016.
- ^Press release Indmatec PEEK MedTec.
- ^Yin, Jun; Zhang, Aiqing; Liew, Kong Yong; Wu, Lihua (2008). "Synthesis of poly(ether ether ketone) assisted by microwave irradiation and its characterization".Polymer Bulletin.61(2): 157–163.doi:10.1007/s00289-008-0942-6.ISSN1436-2449.S2CID97563069.
- ^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.
