Polyetherketone PEK
Poly(ether ketone), an aromatic repeat unit with one ether link and one ketone link (structure drawn in Table 1 of Shabaev et al.)
Also known as VICTREX HT P22, VICTREX HT P45, VICTREX HT G22, VICTREX HT G45
PEK is a semi-crystalline aromatic polyether ketone (PAEK) with one ether link and one ketone link per repeat unit.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Stiffness
4300 MPa
Heat
163 °C deflection temperature
Yield strength
115 MPa
Recipe, share of the weight
- O not statedEther link
- CO not statedKetone link
- C6H4 not statedAromatic ring
Best for
Stiff, heat-tolerant thermoplastic parts that need about 4300 MPa tensile modulus at 23 °C and a deflection temperature of 163 °C (VICTREX HT G22)
Weakest at
Flexural strength at high temperature (32.0 MPa at 175 °C for G22, against 180 MPa at 23 °C), and no space-environment data
Risk at a glance
- People None found. Not classified in the sources read
- If it fails High. Strength loss at elevated temperature
- Corrosion Low. PEK takes up 0.60 % water at saturation at 23 °C and 0.75 % at 100 °C.
Quick facts: PEK
| Property | Value | Basis |
|---|---|---|
| Density | 1.3 g/cm³ | 1 sourced value |
| Yield strength | 100 to 115 MPa | 4 sourced values across conditions |
| Young's modulus | 4.2 to 4.3 GPa | 4 sourced values across conditions |
| Thermal conductivity | 0.29 W/m/K | 1 sourced value |
| Thermal expansion (CTE) | 55 ppm/K | 1 sourced value |
| Melting point | 335 to 391 °C | 4 sourced values across conditions |
| Specific heat | 2,200 J/kg/°C | 1 sourced value |
What is the density of Polyetherketone (PEK)?
Polyetherketone (PEK) has a density of 1.3 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Polyetherketone (PEK)?
Polyetherketone (PEK) has a thermal conductivity of 0.29 W/m/K. The source and test conditions are listed in the properties table on this page.
What is the coefficient of thermal expansion of Polyetherketone (PEK)?
Polyetherketone (PEK) has a coefficient of thermal expansion of 55 ppm/K. The source and test conditions are listed in the properties table on this page.
What is the melting point of Polyetherketone (PEK)?
Polyetherketone (PEK) has a melting point of 335 to 391 °C. The range covers 4 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the yield strength of Polyetherketone (PEK)?
Polyetherketone (PEK) has a yield strength of 100 to 115 MPa. The range covers 4 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What are the other names and codes for Polyetherketone (PEK)?
Polyetherketone (PEK) is also written as VICTREX HT P22, VICTREX HT P45, VICTREX HT G22, VICTREX HT G45. Each code is printed in the source listed beside it in the designations table.
What is Polyetherketone (PEK) used for?
Uses recorded in the sources include Injection-moulded PEK parts from VICTREX HT G22 or G45 granules (product statement; no specific part named); Electrically insulating moulded PEK parts (datasheet properties only).
Why it exists
PEK is a semi-crystalline PAEK thermoplastic, the same chemical family as PEEK and PEKK. Its repeat unit has one ether link and one ketone link, against two ether links for PEEK. More ketone links raise the melting point and glass transition temperature: in the Shabaev table PEK at 50 % ketone melts at 365 °C and PEEK at 33 % melts at 335 °C. Victrex makes PEK as the HT line, and its datasheets give a glass transition midpoint of 160 °C and a melting temperature of 373 °C.
Where it's used
Injection-moulded structural parts
Victrex describes G22 and G45 for high strength and stiffness with good ductility at higher temperatures. The datasheet names no specific part, and no part-level test was read.
Electrical insulation
The G22 sheet prints a dielectric strength of 23.0 kV/mm at 2.00 mm and a comparative tracking index of 150 V.
Recipe
Poly(ether ketone), an aromatic repeat unit with one ether link and one ketone link (structure drawn in Table 1 of Shabaev et al.)
PEK is an aromatic polyether ketone. Each repeat unit carries one ether link and one ketone link between aromatic rings, which keeps the chain stiff. The VICTREX HT grades are unreinforced PEK, supplied as coarse powder (P grades, for extrusion compounding) or depth-filtered granules (G grades, for injection moulding). The monomers and the manufacturing route were not read in this run.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Ether link O | not stated | Aryl ether link in each repeat unit; one ether link per unit distinguishes PEK from PEEK. |
| Ketone link CO | not stated | Carbonyl link; more ketone links raise melting and glass transition temperatures (Table 2 of Shabaev et al.). |
| Aromatic ring C6H4 | not stated | Phenylene unit linking the ether and ketone groups. |
Weight shares are as printed in the sources.
What it can do
Stiffness
4300 MPa
The G22 and P22 grades have a tensile modulus of 4300 MPa at 23 °C, and P45 and G45 have 4200 MPa, all from ISO 527-1 datasheet values.
Heat
163 °C deflection temperature
G22 has a deflection temperature under load of 163 °C at 1.8 MPa and a melting temperature of 373 °C. Flexural strength falls well before the melt, as the 175 °C value shows.
Yield strength
115 MPa
G22 yield stress is 115 MPa at 23 °C in ISO 527-2 tension.
How it compares
Against PEEK, the Shabaev Table 2 gives PEK at 50 % ketone a melting point of 365 °C and glass transition of 152 °C, against 335 °C and 141 °C for PEEK at 33 % ketone. Against PEKK, PEK is lower again: PEKK at 67 % ketone melts at 391 °C with a glass transition of 165 °C. The Victrex HT tensile moduli of 4200 to 4300 MPa and yield stresses of 100 to 115 MPa are datasheet nominal values. No PEEK datasheet value from the same run is used here.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | PEK | PAI | PBI | PBO (Zylon) | PEEK | PEI | PEKK | PES | PPS | PPSU | PSU |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Thermal behavior and safety | |||||||||||
| Deflection temperature under load, VICTREX HT G22 | 163 °C16 | 278 °C | 435 °C | no data | no data | 173 °C | 164 °C | 205 °C | 400 °F | 207 °C | 174 °C |
| Melting temperature, VICTREX HT P45 | 373 °C18 | no data | no data | no data | 343 °C | no data | 360 °C | no data | 536 °F | no data | no data |
| Thermal conductivity (average), VICTREX HT G22 | 0.29 W/m/K19 | 0.53 W/m/K | 0.41 W m-1 K-1 | no data | 0.29 W/(m K) | 0.22 W/m-°C | no data | no data | no data | no data | no data |
| Specific heat capacity, VICTREX HT G45 | 2200 J/kg/°C21 | no data | no data | no data | no data | no data | 1.02 J/g/K | no data | no data | no data | no data |
| Melting temperature, PEK with 50 % ketone groups | 365 °C27 | no data | no data | no data | 343 °C | no data | 360 °C | no data | 536 °F | no data | no data |
| Melting temperature, PEEK with 33 % ketone groups | 335 °C29 | no data | no data | no data | 343 °C | no data | 360 °C | no data | 536 °F | no data | no data |
| Melting temperature, PEKK with 67 % ketone groups | 391 °C31 | no data | no data | no data | 343 °C | no data | 360 °C | no data | 536 °F | no data | no data |
| Physical and electrical | |||||||||||
| Density (crystalline), VICTREX HT P45 | 1.3 g/cm³1 | 1.41 g/cc | 1.276 g/cm³ | 1.398 g/cm³ | 1.3 g/cm³ | 1.34 g/cm³ | 1.29 g/cm³ | 1370 kg/m3 | 1.36 g/cm³ | 1.29 g/cm³ | 1.22 g/cm³ |
| Temperature behavior | |||||||||||
| Glass transition temperature (midpoint), VICTREX HT P45 | 160 °C17 | 275 °C | 425 °C | no data | no data | 186 °C | 165 °C | 225 °C | 90 °C | 220 °C | 190 °C |
| Glass transition temperature, PEK with 50 % ketone groups | 152 °C28 | 275 °C | 425 °C | no data | no data | 186 °C | 165 °C | 225 °C | 90 °C | 220 °C | 190 °C |
| Glass transition temperature, PEEK with 33 % ketone groups | 141 °C30 | 275 °C | 425 °C | no data | no data | 186 °C | 165 °C | 225 °C | 90 °C | 220 °C | 190 °C |
| Glass transition temperature, PEKK with 67 % ketone groups | 165 °C32 | 275 °C | 425 °C | no data | no data | 186 °C | 165 °C | 225 °C | 90 °C | 220 °C | 190 °C |
| Other measurements | |||||||||||
| Tensile modulus, VICTREX HT G22 | 4300 MPa2 | 4136 MPa | 5.9 GPa | 147.1 GPa | no data | 3200 MPa | 4000 MPa | 2640 MPa | 8.37×10^5 psi | 2340 MPa | 2480 MPa |
| Tensile modulus, VICTREX HT P22 | 4300 MPa3 | 4136 MPa | 5.9 GPa | 147.1 GPa | no data | 3200 MPa | 4000 MPa | 2640 MPa | 8.37×10^5 psi | 2340 MPa | 2480 MPa |
| Tensile modulus, VICTREX HT P45 | 4200 MPa4 | 4136 MPa | 5.9 GPa | 147.1 GPa | no data | 3200 MPa | 4000 MPa | 2640 MPa | 8.37×10^5 psi | 2340 MPa | 2480 MPa |
| Tensile modulus, VICTREX HT G45 | 4200 MPa5 | 4136 MPa | 5.9 GPa | 147.1 GPa | no data | 3200 MPa | 4000 MPa | 2640 MPa | 8.37×10^5 psi | 2340 MPa | 2480 MPa |
| Tensile yield stress, VICTREX HT G22 | 115 MPa6 | no data | no data | no data | no data | 110 MPa | 110 to 120 MPa | 86 MPa | 13700 psi | 74 MPa | no data |
| Tensile yield stress, VICTREX HT P22 | 100 MPa7 | no data | no data | no data | no data | 110 MPa | 110 to 120 MPa | 86 MPa | 13700 psi | 74 MPa | no data |
| Tensile yield stress, VICTREX HT P45 | 100 MPa8 | no data | no data | no data | no data | 110 MPa | 110 to 120 MPa | 86 MPa | 13700 psi | 74 MPa | no data |
| Tensile yield stress, VICTREX HT G45 | 110 MPa9 | no data | no data | no data | no data | 110 MPa | 110 to 120 MPa | 86 MPa | 13700 psi | 74 MPa | no data |
| Elongation at break, VICTREX HT G22 | 15 %10 | 20 % | 3 % | 3.52 % | no data | 50 % | 3 to 10 % | no data | 2.5 % | 60 to 120 % | 50 % |
| Elongation at break, VICTREX HT P22 | 10 %11 | 20 % | 3 % | 3.52 % | no data | 50 % | 3 to 10 % | no data | 2.5 % | 60 to 120 % | 50 % |
| Elongation at break, VICTREX HT G45 | 20 %12 | 20 % | 3 % | 3.52 % | no data | 50 % | 3 to 10 % | no data | 2.5 % | 60 to 120 % | 50 % |
| Flexural modulus, VICTREX HT G22 | 4000 MPa13 | 4136 MPa | no data | no data | no data | 2400 MPa | 3.9 GPa | no data | 6.31×10^5 psi | 2410 MPa | 2690 MPa |
| Flexural stress, VICTREX HT P45 | 170 MPa14 | 165 MPa | no data | no data | no data | 100 MPa | 180 MPa | no data | 20400 psi | 91 MPa | 106 MPa |
| Flexural stress at 175 °C, VICTREX HT G22 | 32 MPa15 | 165 MPa | no data | no data | no data | 100 MPa | 180 MPa | no data | 20400 psi | 91 MPa | 106 MPa |
| Coefficient of linear thermal expansion (average, below 152 °C), VICTREX HT G22 | 55 ppm/K20 | 3.1×10^-5 1/°C | 23 10-6 K-1 | no data | no data | 5.2×10^-5 1/°C | 23 µm/m/K | 52 E-6/K | 2.6×10^-5 cm/cm/°C | 55 E-6/K | 5.6×10^-5 1/°C |
| Water absorption at saturation, 23 °C, VICTREX HT G22 | 0.6 %22 | 0.4 % | 0.4 % | no data | no data | 0.25 % | 0.4 % | 2.2 % | 0.01 % | 1.1 % | 0.3 % |
| Water absorption at saturation, 100 °C, VICTREX HT G22 | 0.75 %23 | 0.4 % | 0.4 % | no data | no data | 0.25 % | 0.4 % | 2.2 % | 0.01 % | 1.1 % | 0.3 % |
| Dielectric strength (2.00 mm), VICTREX HT G22 | 23 kV/mm24 | 580 V/mil | 21 kV/mm | no data | no data | no data | 84 kV/mm | 37 kV/mm | 450 V/mil | 15 kV/mm | 17 kV/mm |
| Charpy notched impact strength (23 °C), VICTREX HT G22 | 3.8 kJ/m225 | no data | no data | no data | no data | no data | 4.5 kJ/m2 | no data | no data | no data | no data |
| Notched Izod impact strength (23 °C), VICTREX HT P45 | 6.5 kJ/m226 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
Why choose it, and why not
Good for
- Stiffness at temperature. G22 has a tensile modulus of 4300 MPa at 23 °C and a deflection temperature of 163 °C.
- Injection moulding. G22 and G45 granules have a printed set of processing conditions.
- Electrical insulation. A dielectric strength of 23.0 kV/mm at 2.00 mm.
Watch out for
- High-temperature strength. Flexural stress is 32.0 MPa at 175 °C against 180 MPa at 23 °C.
- No space data. No atomic-oxygen, outgassing, UV or ageing number for PEK was read.
- Grade differences. Elongation at break is 10 % for P22, 15 % for G22 and 20 % for G45 on the Victrex sheets.
PEK, as Victrex's HT line, is a stiff, heat-tolerant semi-crystalline thermoplastic with datasheet values near 4300 MPa modulus, a glass transition of 160 °C and a melting temperature of 373 °C. The record has no space-ageing data and no hazard classification, so treat any orbital or hazardous use as untested.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| Trade name | VICTREX HT P22, VICTREX HT P45, VICTREX HT G22, VICTREX HT G45 |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density (crystalline), VICTREX HT P45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P45 (coarse powder for extrusion compounding)test standard ISO 1183state crystalline | The same 1.30 g/cm3 is printed for the P22, G22 and G45 grades. |
| 2 | Tensile modulus, VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (depth-filtered granules for injection moulding)test standard ISO 527-1temperature 23 °C | — |
| 3 | Tensile modulus, VICTREX HT P22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P22 (coarse powder for extrusion compounding)test standard ISO 527-1temperature 23 °C | — |
| 4 | Tensile modulus, VICTREX HT P45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P45 (coarse powder for extrusion compounding)test standard ISO 527-1temperature 23 °C | — |
| 5 | Tensile modulus, VICTREX HT G45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G45 (depth-filtered granules, low flow, injection moulding)test standard ISO 527-1temperature 23 °C | — |
| 6 | Tensile yield stress, VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 527-2temperature 23 °C | — |
| 7 | Tensile yield stress, VICTREX HT P22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P22 (coarse powder for extrusion compounding)test standard ISO 527-2temperature 23 °C | — |
| 8 | Tensile yield stress, VICTREX HT P45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P45 (coarse powder for extrusion compounding)test standard ISO 527-2temperature 23 °C | — |
| 9 | Tensile yield stress, VICTREX HT G45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G45 (injection moulding granules, low flow)test standard ISO 527-2temperature 23 °C | — |
| 10 | Elongation at break, VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 527-2temperature 23 °C | — |
| 11 | Elongation at break, VICTREX HT P22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P22 (coarse powder for extrusion compounding)test standard ISO 527-2temperature 23 °C | — |
| 12 | Elongation at break, VICTREX HT G45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G45 (injection moulding granules, low flow)test standard ISO 527-2temperature 23 °C | Elongation at break is 10 % for P22 and 15 % for G22 on the same kind of sheet, so the grade and form matter. |
| 13 | Flexural modulus, VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 178temperature 23 °C | — |
| 14 | Flexural stress, VICTREX HT P45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P45 (coarse powder for extrusion compounding)test standard ISO 178temperature 23 °C | — |
| 15 | Flexural stress at 175 °C, VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 178temperature 175 °Cbasis printed under the 3.5 % strain heading in the sheet layout | The same sheet gives 180 MPa at 23 °C (a footnote marks it as the value at yield) and 105 MPa at 125 °C. Read the heading as printed; it is not confirmed as maximum strength. |
| 16 | Deflection temperature under load, VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 75-2/Af, 1.8 MPastate unannealed | — |
| 17 | Glass transition temperature (midpoint), VICTREX HT P45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P45 (coarse powder for extrusion compounding)test standard ISO 11357-2point midpoint | The onset on the same sheet is 152 °C. The P22, G22 and G45 sheets print the same onset and midpoint. |
| 18 | Melting temperature, VICTREX HT P45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P45 (coarse powder for extrusion compounding)test standard ISO 11357-3 | The P22, G22 and G45 sheets print the same 373 °C melting temperature. |
| 19 | Thermal conductivity (average), VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 22007-4temperature 23 °Cdirection average | Along the flow direction the same sheet gives 0.32 W/m/K. |
| 20 | Coefficient of linear thermal expansion (average, below 152 °C), VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 11359-2temperature below 152 °Cdirection average | Above 152 °C the average CLTE is 130 ppm/K, and the flow-direction values are 45 and 75 ppm/K for below and above 152 °C. |
| 21 | Specific heat capacity, VICTREX HT G45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G45 (injection moulding granules, low flow)method detail DSCtemperature 23 °C | — |
| 22 | Water absorption at saturation, 23 °C, VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 62temperature 23 °Cstate saturation | — |
| 23 | Water absorption at saturation, 100 °C, VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 62temperature 100 °Cstate saturation | — |
| 24 | Dielectric strength (2.00 mm), VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard IEC 60243-1thickness 2.00 mm | The same sheet prints a comparative tracking index of 150 V (IEC 60112). |
| 25 | Charpy notched impact strength (23 °C), VICTREX HT G22 | Value listed in the manufacturer's online datasheet | grade VICTREX HT G22 (injection moulding granules)test standard ISO 179/1eAtemperature 23 °C | — |
| 26 | Notched Izod impact strength (23 °C), VICTREX HT P45 | Value listed in the manufacturer's online datasheet | grade VICTREX HT P45 (coarse powder for extrusion compounding)test standard ISO 180/Atemperature 23 °C | — |
| 27 | Melting temperature, PEK with 50 % ketone groups | Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15 | basis PEK with 50 % of groups as ketone, PEK row of Table 2 of Shabaev et al.ketone fraction percent 50 | — |
| 28 | Glass transition temperature, PEK with 50 % ketone groups | Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15 | basis PEK with 50 % of groups as ketone, PEK row of Table 2 of Shabaev et al.ketone fraction percent 50 | — |
| 29 | Melting temperature, PEEK with 33 % ketone groups | Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15 | basis PEEK with 33 % of groups as ketone, PEEK row of Table 2 of Shabaev et al.ketone fraction percent 33 | — |
| 30 | Glass transition temperature, PEEK with 33 % ketone groups | Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15 | basis PEEK with 33 % of groups as ketone, PEEK row of Table 2 of Shabaev et al.ketone fraction percent 33 | — |
| 31 | Melting temperature, PEKK with 67 % ketone groups | Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15 | basis PEKK with 67 % of groups as ketone, PEKK row of Table 2 of Shabaev et al.ketone fraction percent 67 | — |
| 32 | Glass transition temperature, PEKK with 67 % ketone groups | Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15 | basis PEKK with 67 % of groups as ketone, PEKK row of Table 2 of Shabaev et al.ketone fraction percent 67 | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Water vapour and immersion at 23 °C and 100 °C | low | PEK takes up 0.60 % water at saturation at 23 °C and 0.75 % at 100 °C.1 |
| Heat over service life | not rated | No long-term heat-ageing test was read; the datasheets give short-term heat values only.2 |
| Ultraviolet light | not rated | No UV-ageing number for PEK was read in this run.3 |
| Chemicals and solvents | not rated | Victrex describes chemical resistance in general terms only.4 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Water vapour and immersion at 23 °C and 100 °C | Saturation water absorption is 0.60 % at 23 °C and 0.75 % at 100 °C (ISO 62, VICTREX HT G22). These are uptake figures; no wet-property or wet-ageing test was read in this run. | grade VICTREX HT G22test standard ISO 62 |
| 2 | Heat over service life | The G22 sheet gives flexural stress of 32.0 MPa at 175 °C and 16.0 MPa at 275 °C (ISO 178), and a deflection temperature of 163 °C at 1.8 MPa. These are short-term values, not ageing results. | basis short-term tests on datasheets |
| 3 | Ultraviolet light | None of the four Victrex HT sheets prints a UV test, and the 2024 paper covers thermal behaviour only. UV and space exposure of PEK remain untested in this record. | basis no UV test printed in the datasheets read |
| 4 | Chemicals and solvents | The G22 and G45 sheets say the grades are chemically resistant to aggressive environments and suitable for sterilisation for medical and food contact. No acid, base or solvent table was read. | basis product description only |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
No Victrex HT safety data sheet was read, so no hazard classification is claimed for PEK.
- Resin and dust
- Handle the powder and granules as dust-generating material and keep dust low during processing. No dust or toxicology data for PEK were read.
- Melt
- The G22 nozzle is set at 395 °C and the G45 nozzle at 415 °C, so hot polymer and fume are a concern. No fume data were read.
If a part fails
These results come from datasheet tests on moulded specimens, not from failures of finished parts.
- Heat
- The G22 sheet gives 32.0 MPa flexural stress at 175 °C, against 180 MPa at 23 °C, so a loaded part should stay well below that temperature.
- Shrinkage
- Mould shrinkage is 1.2 % across flow and 1.0 % along flow for G22, so moulded parts need a design allowance for direction.
Handling and storage
- Drying
- Dry before processing at 150 °C for 3 h or 120 °C for 5 h, to residual moisture below 0.02 %.
- Storage
- No storage-life statement was read for the HT grades. Keep the material sealed so it does not take up moisture before drying.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Strength loss at elevated temperaturehigh severity | Flexural loading at 175 °C (G22, ISO 178)Flexural stress at 175 °C is 32.0 MPa, against 180 MPa at 23 °C, so a loaded part should stay well below that temperature. |
| Anisotropic shrinkage in moulded partsmoderate severity | Injection moulding of G22 granulesMould shrinkage is 1.2 % across flow and 1.0 % along flow, and the CLTE differs between flow and average directions, so moulded parts need direction-specific allowance. |
| Moisture uptakelow severity | Immersion or humid storageUptake is 0.60 % at saturation at 23 °C and 0.75 % at 100 °C, small but not zero; no wet-property data were read. |
Handling and storage
- Dry before melt processing at 150 °C for 3 h or 120 °C for 5 h, to residual moisture below 0.02 %.
- G22 injection set points: rear 375 °C, middle 380 to 385 °C, front 390 °C, nozzle 395 °C, mould 190 to 215 °C.
- G45 injection set points: rear 390 °C, middle 395 to 405 °C, front 410 °C, nozzle 415 °C, mould 200 to 220 °C.
Supply and geography
How common the raw materials are and where they come from.
PEK polymer (VICTREX HT line)
Documents
Datasheets, safety data sheets, papers and standards you can open.
| Document | Type | Year |
|---|---|---|
| VICTREX HT POLYMER P22 datasheet | datasheet | 2026 |
| VICTREX HT POLYMER P45 datasheet | datasheet | 2026 |
| VICTREX HT POLYMER G22 datasheet | datasheet | 2026 |
| VICTREX HT POLYMER G45 datasheet | datasheet | 2026 |
| Thermal transformation and mechanical properties of high-temperature-resistant matrix based polyetherketones (open access) | paper | 2024 |
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
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spore: profile
id: pek
spore_version: 0.2
family: high-performance-polymers
name: Polyetherketone
abbreviation: PEK
role: structural/insulating polymer
category: polymers
type: high-performance
summary: |
PEK is a semi-crystalline aromatic polyether ketone (PAEK) with one ether link and one ketone link per repeat unit. Victrex sells it as the VICTREX HT line, which is PEK, not PEKK. The P22, P45 and G22 datasheets all give a glass transition midpoint of 160 °C and a melting temperature of 373 °C, and the G22 injection-moulding grade has a tensile modulus of 4300 MPa at 23 °C and a deflection temperature of 163 °C at 1.8 MPa. A 2024 open-access paper gives PEK melting at 365 °C and glass transition at 152 °C for a 50 % ketone fraction, against 335 °C and 141 °C for PEEK at 33 %. No atomic-oxygen, outgassing, UV or long-term heat-ageing number for PEK was read in this run.
best_for: Stiff, heat-tolerant thermoplastic parts that need about 4300 MPa tensile modulus at 23 °C and a deflection temperature of 163 °C (VICTREX HT G22)
weakest_at: Flexural strength at high temperature (32.0 MPa at 175 °C for G22, against 180 MPa at 23 °C), and no space-environment data
identity:
formula: Poly(ether ketone), an aromatic repeat unit with one ether link and one ketone link (structure drawn in Table 1 of Shabaev et al.)
source: shabaev2024
where: Table 1, PEK structure with one ether and one ketone link per repeat unit; the VICTREX HT G22 datasheet describes the grade as unreinforced PolyEtherKetone (PEK)
designations:
- system: Trade name
code: VICTREX HT P22
source: victrex-ht-p22
where: Page title and breadcrumb
- system: Trade name
code: VICTREX HT P45
source: victrex-ht-p45
where: Page title and breadcrumb
- system: Trade name
code: VICTREX HT G22
source: victrex-ht-g22
where: Page title and breadcrumb
- system: Trade name
code: VICTREX HT G45
source: victrex-ht-g45
where: Page title and breadcrumb
tags:
environments: []
stresses:
- extreme-heat
applications:
- structures
- electronics-and-chips
properties:
- benchmark: density
label: Density (crystalline), VICTREX HT P45
value: 1.3
unit: g/cm3
scope: material
conditions:
grade: VICTREX HT P45 (coarse powder for extrusion compounding)
test_standard: ISO 1183
state: crystalline
method: Value listed in the manufacturer's online datasheet
status: ground
note: The same 1.30 g/cm3 is printed for the P22, G22 and G45 grades.
source: victrex-ht-p45
where: Material Properties, Physical, Density (Crystalline) row
- benchmark: elastic_modulus
label: Tensile modulus, VICTREX HT G22
value: 4300
unit: MPa
scope: material
conditions:
grade: VICTREX HT G22 (depth-filtered granules for injection moulding)
test_standard: ISO 527-1
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g22
where: Mechanical, Tensile Modulus (23°C) row
- benchmark: elastic_modulus
label: Tensile modulus, VICTREX HT P22
value: 4300
unit: MPa
scope: material
conditions:
grade: VICTREX HT P22 (coarse powder for extrusion compounding)
test_standard: ISO 527-1
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-p22
where: Mechanical, Tensile Modulus (23°C) row
- benchmark: elastic_modulus
label: Tensile modulus, VICTREX HT P45
value: 4200
unit: MPa
scope: material
conditions:
grade: VICTREX HT P45 (coarse powder for extrusion compounding)
test_standard: ISO 527-1
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-p45
where: Mechanical, Tensile Modulus (23°C) row
- benchmark: elastic_modulus
label: Tensile modulus, VICTREX HT G45
value: 4200
unit: MPa
scope: material
conditions:
grade: VICTREX HT G45 (depth-filtered granules, low flow, injection moulding)
test_standard: ISO 527-1
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g45
where: Mechanical, Tensile Modulus (23°C) row
- benchmark: yield_strength
label: Tensile yield stress, VICTREX HT G22
value: 115
unit: MPa
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 527-2
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g22
where: Mechanical, Tensile Stress (Yield, 23°C) row
- benchmark: yield_strength
label: Tensile yield stress, VICTREX HT P22
value: 100
unit: MPa
scope: material
conditions:
grade: VICTREX HT P22 (coarse powder for extrusion compounding)
test_standard: ISO 527-2
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-p22
where: Mechanical, Tensile Stress (Yield, 23°C) row
- benchmark: yield_strength
label: Tensile yield stress, VICTREX HT P45
value: 100
unit: MPa
scope: material
conditions:
grade: VICTREX HT P45 (coarse powder for extrusion compounding)
test_standard: ISO 527-2
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-p45
where: Mechanical, Tensile Stress (Yield, 23°C) row
- benchmark: yield_strength
label: Tensile yield stress, VICTREX HT G45
value: 110
unit: MPa
scope: material
conditions:
grade: VICTREX HT G45 (injection moulding granules, low flow)
test_standard: ISO 527-2
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g45
where: Mechanical, Tensile Stress (Yield, 23°C) row
- benchmark: elongation
label: Elongation at break, VICTREX HT G22
value: 15
unit: '%'
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 527-2
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g22
where: Mechanical, Tensile Strain (Break, 23°C) row
- benchmark: elongation
label: Elongation at break, VICTREX HT P22
value: 10
unit: '%'
scope: material
conditions:
grade: VICTREX HT P22 (coarse powder for extrusion compounding)
test_standard: ISO 527-2
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-p22
where: Mechanical, Tensile Strain (Break, 23°C) row
- benchmark: elongation
label: Elongation at break, VICTREX HT G45
value: 20
unit: '%'
scope: material
conditions:
grade: VICTREX HT G45 (injection moulding granules, low flow)
test_standard: ISO 527-2
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
note: Elongation at break is 10 % for P22 and 15 % for G22 on the same kind of sheet, so the grade and form matter.
source: victrex-ht-g45
where: Mechanical, Tensile Strain (Break, 23°C) row
- benchmark: flexural_modulus
label: Flexural modulus, VICTREX HT G22
value: 4000
unit: MPa
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 178
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g22
where: Mechanical, Flexural Modulus (23°C) row
- benchmark: flexural_strength
label: Flexural stress, VICTREX HT P45
value: 170
unit: MPa
scope: material
conditions:
grade: VICTREX HT P45 (coarse powder for extrusion compounding)
test_standard: ISO 178
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-p45
where: Mechanical, Flexural Stress (23°C) row
- benchmark: flexural_strength
label: Flexural stress at 175 °C, VICTREX HT G22
value: 32
unit: MPa
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 178
temperature: 175 °C
basis: printed under the 3.5 % strain heading in the sheet layout
method: Value listed in the manufacturer's online datasheet
status: ground
note: The same sheet gives 180 MPa at 23 °C (a footnote marks it as the value at yield) and 105 MPa at 125 °C. Read the heading as printed; it is not confirmed as maximum strength.
source: victrex-ht-g22
where: Mechanical, Flexural Stress, 175°C row
- benchmark: heat_deflection_temperature
label: Deflection temperature under load, VICTREX HT G22
value: 163
unit: °C
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 75-2/Af, 1.8 MPa
state: unannealed
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g22
where: Thermal, Deflection Temperature Under Load (1.8 MPa, Unannealed) row
- benchmark: glass_transition_temperature
label: Glass transition temperature (midpoint), VICTREX HT P45
value: 160
unit: °C
scope: material
conditions:
grade: VICTREX HT P45 (coarse powder for extrusion compounding)
test_standard: ISO 11357-2
point: midpoint
method: Value listed in the manufacturer's online datasheet
status: ground
note: The onset on the same sheet is 152 °C. The P22, G22 and G45 sheets print the same onset and midpoint.
source: victrex-ht-p45
where: Thermal, Glass Transition Temperature, Midpoint row
- benchmark: melting_point
label: Melting temperature, VICTREX HT P45
value: 373
unit: °C
scope: material
conditions:
grade: VICTREX HT P45 (coarse powder for extrusion compounding)
test_standard: ISO 11357-3
method: Value listed in the manufacturer's online datasheet
status: ground
note: The P22, G22 and G45 sheets print the same 373 °C melting temperature.
source: victrex-ht-p45
where: Thermal, Melting Temperature row
- benchmark: thermal_conductivity
label: Thermal conductivity (average), VICTREX HT G22
value: 0.29
unit: W/m/K
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 22007-4
temperature: 23 °C
direction: average
method: Value listed in the manufacturer's online datasheet
status: ground
note: Along the flow direction the same sheet gives 0.32 W/m/K.
source: victrex-ht-g22
where: Thermal, Thermal Conductivity, 23°C average row
- benchmark: cte
label: Coefficient of linear thermal expansion (average, below 152 °C), VICTREX HT G22
value: 55
unit: ppm/K
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 11359-2
temperature: below 152 °C
direction: average
method: Value listed in the manufacturer's online datasheet
status: ground
note: Above 152 °C the average CLTE is 130 ppm/K, and the flow-direction values are 45 and 75 ppm/K for below and above 152 °C.
source: victrex-ht-g22
where: Thermal, CLTE Average row
- benchmark: specific_heat
label: Specific heat capacity, VICTREX HT G45
value: 2200
unit: J/kg/°C
scope: material
conditions:
grade: VICTREX HT G45 (injection moulding granules, low flow)
method_detail: DSC
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g45
where: Thermal, Specific Heat (23°C) row
- benchmark: moisture_absorption
label: Water absorption at saturation, 23 °C, VICTREX HT G22
value: 0.6
unit: '%'
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 62
temperature: 23 °C
state: saturation
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g22
where: Physical, Water Absorption Saturation (23°C) row
- benchmark: moisture_absorption
label: Water absorption at saturation, 100 °C, VICTREX HT G22
value: 0.75
unit: '%'
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 62
temperature: 100 °C
state: saturation
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g22
where: Physical, Water Absorption Saturation (100°C) row
- benchmark: dielectric_strength
label: Dielectric strength (2.00 mm), VICTREX HT G22
value: 23
unit: kV/mm
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: IEC 60243-1
thickness: 2.00 mm
method: Value listed in the manufacturer's online datasheet
status: ground
note: The same sheet prints a comparative tracking index of 150 V (IEC 60112).
source: victrex-ht-g22
where: Electrical, Dielectric Strength (2.00 mm) row
- benchmark: charpy_notched_impact
label: Charpy notched impact strength (23 °C), VICTREX HT G22
value: 3.8
unit: kJ/m2
scope: material
conditions:
grade: VICTREX HT G22 (injection moulding granules)
test_standard: ISO 179/1eA
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-g22
where: Impact, Charpy Notched Impact Strength (23°C) row
- benchmark: notched_izod_impact_strength
label: Notched Izod impact strength (23 °C), VICTREX HT P45
value: 6.5
unit: kJ/m2
scope: material
conditions:
grade: VICTREX HT P45 (coarse powder for extrusion compounding)
test_standard: ISO 180/A
temperature: 23 °C
method: Value listed in the manufacturer's online datasheet
status: ground
source: victrex-ht-p45
where: Impact, Notched Izod Impact Strength (23°C) row
- benchmark: melting_point
label: Melting temperature, PEK with 50 % ketone groups
value: 365
unit: °C
scope: material
conditions:
basis: PEK with 50 % of groups as ketone, PEK row of Table 2 of Shabaev et al.
ketone_fraction_percent: 50
method: Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15
status: ground
source: shabaev2024
where: Table 2, PEK row (50 % ketone groups)
- benchmark: glass_transition_temperature
label: Glass transition temperature, PEK with 50 % ketone groups
value: 152
unit: °C
scope: material
conditions:
basis: PEK with 50 % of groups as ketone, PEK row of Table 2 of Shabaev et al.
ketone_fraction_percent: 50
method: Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15
status: ground
source: shabaev2024
where: Table 2, PEK row (50 % ketone groups)
- benchmark: melting_point
label: Melting temperature, PEEK with 33 % ketone groups
value: 335
unit: °C
scope: material
conditions:
basis: PEEK with 33 % of groups as ketone, PEEK row of Table 2 of Shabaev et al.
ketone_fraction_percent: 33
method: Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15
status: ground
source: shabaev2024
where: Table 2, PEEK row (33 % ketone groups)
- benchmark: glass_transition_temperature
label: Glass transition temperature, PEEK with 33 % ketone groups
value: 141
unit: °C
scope: material
conditions:
basis: PEEK with 33 % of groups as ketone, PEEK row of Table 2 of Shabaev et al.
ketone_fraction_percent: 33
method: Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15
status: ground
source: shabaev2024
where: Table 2, PEEK row (33 % ketone groups)
- benchmark: melting_point
label: Melting temperature, PEKK with 67 % ketone groups
value: 391
unit: °C
scope: material
conditions:
basis: PEKK with 67 % of groups as ketone, PEKK row of Table 2 of Shabaev et al.
ketone_fraction_percent: 67
method: Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15
status: ground
source: shabaev2024
where: Table 2, PEKK row (67 % ketone groups)
- benchmark: glass_transition_temperature
label: Glass transition temperature, PEKK with 67 % ketone groups
value: 165
unit: °C
scope: material
conditions:
basis: PEKK with 67 % of groups as ketone, PEKK row of Table 2 of Shabaev et al.
ketone_fraction_percent: 67
method: Value tabulated in a 2024 open-access paper, compiled by the paper from its ref. 15
status: ground
source: shabaev2024
where: Table 2, PEKK row (67 % ketone groups)
sources:
victrex-ht-p22:
title: VICTREX HT POLYMER P22 datasheet, unreinforced PEK, coarse powder for extrusion compounding
id: Victrex online datasheet, last updated 17 March 2026
url: https://www.victrex.com/en/downloads/datasheets/victrex-ht-p22
year: 2026
kind: datasheet
license: manufacturer document, linked not reproduced
victrex-ht-p45:
title: VICTREX HT POLYMER P45 datasheet, unreinforced PEK, coarse powder for extrusion compounding
id: Victrex online datasheet, last updated 17 March 2026
url: https://www.victrex.com/en/downloads/datasheets/victrex-ht-p45
year: 2026
kind: datasheet
license: manufacturer document, linked not reproduced
victrex-ht-g22:
title: VICTREX HT POLYMER G22 datasheet, unreinforced PEK, depth filtered granules for injection moulding
id: Victrex online datasheet, last updated 17 March 2026
url: https://www.victrex.com/en/downloads/datasheets/victrex-ht-g22
year: 2026
kind: datasheet
license: manufacturer document, linked not reproduced
victrex-ht-g45:
title: VICTREX HT POLYMER G45 datasheet, unreinforced PEK, depth filtered granules, low flow
id: Victrex online datasheet, last updated 17 March 2026
url: https://www.victrex.com/en/downloads/datasheets/victrex-ht-g45
year: 2026
kind: datasheet
license: manufacturer document, linked not reproduced
shabaev2024:
title: Thermal transformation and mechanical properties of high-temperature-resistant matrix based polyetherketones
id: doi:10.18149/MPM.5222024_13 (Materials Physics and Mechanics 52(2), 123-132)
url: https://mpm.spbstu.ru/userfiles/files/13-A_S_-Shabaev%2C-et.pdf
year: 2024
kind: paper
license: CC BY-NC 4.0
license: CC-BY-4.0
updated: '2026-10-26'
review:
status: draft
method: assistant
checked_values: 32
unreachable: 2
caveats: 4
note: Written by an AI assistant on 2026-10-26. Values come from four Victrex HT datasheets read as page text and from Table 2 of the Shabaev 2024 paper (PDF text). The Victrex HT safety data sheet, a PEK CAS number and any space-environment source were not found.
corrosion:
- environment: Water vapour and immersion at 23 °C and 100 °C
headline: PEK takes up 0.60 % water at saturation at 23 °C and 0.75 % at 100 °C.
effect: Saturation water absorption is 0.60 % at 23 °C and 0.75 % at 100 °C (ISO 62, VICTREX HT G22). These are uptake figures; no wet-property or wet-ageing test was read in this run.
rating: low
conditions:
grade: VICTREX HT G22
test_standard: ISO 62
source: victrex-ht-g22
where: Physical, Water Absorption Saturation rows
- environment: Heat over service life
headline: No long-term heat-ageing test was read; the datasheets give short-term heat values only.
effect: The G22 sheet gives flexural stress of 32.0 MPa at 175 °C and 16.0 MPa at 275 °C (ISO 178), and a deflection temperature of 163 °C at 1.8 MPa. These are short-term values, not ageing results.
rating: unknown
conditions:
basis: short-term tests on datasheets
source: victrex-ht-g22
where: Mechanical, Flexural Stress rows; Thermal, Deflection Temperature Under Load row
- environment: Ultraviolet light
headline: No UV-ageing number for PEK was read in this run.
effect: None of the four Victrex HT sheets prints a UV test, and the 2024 paper covers thermal behaviour only. UV and space exposure of PEK remain untested in this record.
rating: unknown
conditions:
basis: no UV test printed in the datasheets read
source: victrex-ht-g22
where: Full sheet read; no UV row present
- environment: Chemicals and solvents
headline: Victrex describes chemical resistance in general terms only.
effect: The G22 and G45 sheets say the grades are chemically resistant to aggressive environments and suitable for sterilisation for medical and food contact. No acid, base or solvent table was read.
rating: unknown
conditions:
basis: product description only
source: victrex-ht-g22
where: Product description
risks:
hazards: []
failure_risks:
- mode: Strength loss at elevated temperature
trigger: Flexural loading at 175 °C (G22, ISO 178)
consequence: Flexural stress at 175 °C is 32.0 MPa, against 180 MPa at 23 °C, so a loaded part should stay well below that temperature.
severity: high
source: victrex-ht-g22
where: Mechanical, Flexural Stress rows
- mode: Anisotropic shrinkage in moulded parts
trigger: Injection moulding of G22 granules
consequence: Mould shrinkage is 1.2 % across flow and 1.0 % along flow, and the CLTE differs between flow and average directions, so moulded parts need direction-specific allowance.
severity: moderate
source: victrex-ht-g22
where: Molding Shrinkage rows; CLTE Flow rows
- mode: Moisture uptake
trigger: Immersion or humid storage
consequence: Uptake is 0.60 % at saturation at 23 °C and 0.75 % at 100 °C, small but not zero; no wet-property data were read.
severity: low
source: victrex-ht-g22
where: Physical, Water Absorption rows
side_effects: []
handling:
- text: Dry before melt processing at 150 °C for 3 h or 120 °C for 5 h, to residual moisture below 0.02 %.
source: victrex-ht-g22
where: Injection Notes, drying line
- text: 'G22 injection set points: rear 375 °C, middle 380 to 385 °C, front 390 °C, nozzle 395 °C, mould 190 to 215 °C.'
source: victrex-ht-g22
where: Typical Processing Information, Injection
- text: 'G45 injection set points: rear 390 °C, middle 395 to 405 °C, front 410 °C, nozzle 415 °C, mould 200 to 220 °C.'
source: victrex-ht-g45
where: Typical Processing Information, Injection
mitigations: []
uses:
- application: structures
device: Injection-moulded PEK parts from VICTREX HT G22 or G45 granules (product statement; no specific part named)
example: The G22 sheet says the grade is for high strength and stiffness and good ductility at higher temperatures, and is suitable for sterilisation for medical and food contact.
source: victrex-ht-g22
where: Product description
- application: electronics-and-chips
device: Electrically insulating moulded PEK parts (datasheet properties only)
example: The G22 sheet lists a dielectric strength of 23.0 kV/mm at 2.00 mm and a comparative tracking index of 150 V. No insulating part was tested in this run.
source: victrex-ht-g22
where: Electrical rows
supply:
- subject: PEK polymer (VICTREX HT line)
producers: []
source: victrex-ht-g22
where: VICTREX HT datasheets carry Victrex branding. No producer country, country shares or company location was read in this run.
documents:
- title: VICTREX HT POLYMER P22 datasheet
type: datasheet
url: https://www.victrex.com/en/downloads/datasheets/victrex-ht-p22
year: 2026
- title: VICTREX HT POLYMER P45 datasheet
type: datasheet
url: https://www.victrex.com/en/downloads/datasheets/victrex-ht-p45
year: 2026
- title: VICTREX HT POLYMER G22 datasheet
type: datasheet
url: https://www.victrex.com/en/downloads/datasheets/victrex-ht-g22
year: 2026
- title: VICTREX HT POLYMER G45 datasheet
type: datasheet
url: https://www.victrex.com/en/downloads/datasheets/victrex-ht-g45
year: 2026
- title: Thermal transformation and mechanical properties of high-temperature-resistant matrix based polyetherketones (open access)
type: paper
url: https://mpm.spbstu.ru/userfiles/files/13-A_S_-Shabaev%2C-et.pdf
year: 2024
gaps:
- No Victrex HT safety data sheet was read. The only Victrex SDS found covers PEEK, so hazards is empty and no hazard class is claimed for PEK.
- No CAS number or PubChem record for PEK was read, so identity has no cas field.
- Monomer formulas, monomer supply and the manufacturing route were not read; the recipe uses the repeat-unit description only.
- No producer country, country shares, feedstock or critical-mineral listing for PEK was found; the Victrex company page was not reachable in this run.
- No atomic-oxygen, outgassing (ECSS), vacuum, radiation or flight result for PEK was found. The search returned PEEK and PEKK results only.
- No UV-ageing or long-term heat-ageing number for PEK was read.
- The G22 flexural stress rows at 125, 175 and 275 degC sit under a 3.5 % strain heading in the sheet layout, and the 180 MPa at 23 degC is footnoted as the value at yield. Read as printed; the heading is not confirmed as maximum strength.
- Victrex HT 22GL30 (glass-fibre reinforced) is listed on Victrex's site but its datasheet was not read, so it is not used as a neat-PEK value.
- charpy_notched_impact and notched_izod_impact_strength are not canonical names in property-canon.yaml; they are kept as snake_case names.
- 'Volume resistivity (1.0E+16 ohms cm on the G22 sheet) and the glow-wire index (960 degC) are left out: the volume resistivity is in E-notation, and the glow-wire index has no canonical name.'
- The Shabaev PEK, PEEK and PEKK rows are literature values compiled by that paper from its ref. 15, not measured by the authors; the PEK 57 percent ketone row prints melting as 374 (416), so it is not used.
- No PEK-specific Wikipedia article was found, so Wikipedia is not used as a source.
- Victrex PEEK 450G values were not re-read in this run, so no same-run PEEK datasheet comparison is made; the PEEK comparison uses the Shabaev Table 2 PEEK row only.
story:
recipe:
line: PEK is an aromatic polyether ketone. Each repeat unit carries one ether link and one ketone link between aromatic rings, which keeps the chain stiff. The VICTREX HT grades are unreinforced PEK, supplied as coarse powder (P grades, for extrusion compounding) or depth-filtered granules (G grades, for injection moulding). The monomers and the manufacturing route were not read in this run.
parts:
- name: Ether link
symbol: O
role: Aryl ether link in each repeat unit; one ether link per unit distinguishes PEK from PEEK.
- name: Ketone link
symbol: CO
role: Carbonyl link; more ketone links raise melting and glass transition temperatures (Table 2 of Shabaev et al.).
- name: Aromatic ring
symbol: C6H4
role: Phenylene unit linking the ether and ketone groups.
risk_groups:
- title: For people
level: 0
verdict: Not classified in the sources read
lead: No Victrex HT safety data sheet was read, so no hazard classification is claimed for PEK.
points:
- label: Resin and dust
line: Handle the powder and granules as dust-generating material and keep dust low during processing. No dust or toxicology data for PEK were read.
- label: Melt
line: The G22 nozzle is set at 395 °C and the G45 nozzle at 415 °C, so hot polymer and fume are a concern. No fume data were read.
- title: If a part fails
lead: These results come from datasheet tests on moulded specimens, not from failures of finished parts.
points:
- label: Heat
line: The G22 sheet gives 32.0 MPa flexural stress at 175 °C, against 180 MPa at 23 °C, so a loaded part should stay well below that temperature.
- label: Shrinkage
line: Mould shrinkage is 1.2 % across flow and 1.0 % along flow for G22, so moulded parts need a design allowance for direction.
- title: Handling and storage
points:
- label: Drying
line: Dry before processing at 150 °C for 3 h or 120 °C for 5 h, to residual moisture below 0.02 %.
- label: Storage
line: No storage-life statement was read for the HT grades. Keep the material sealed so it does not take up moisture before drying.
why: 'PEK is a semi-crystalline PAEK thermoplastic, the same chemical family as PEEK and PEKK. Its repeat unit has one ether link and one ketone link, against two ether links for PEEK. More ketone links raise the melting point and glass transition temperature: in the Shabaev table PEK at 50 % ketone melts at 365 °C and PEEK at 33 % melts at 335 °C. Victrex makes PEK as the HT line, and its datasheets give a glass transition midpoint of 160 °C and a melting temperature of 373 °C.'
uses:
- where: Injection-moulded structural parts
line: Victrex describes G22 and G45 for high strength and stiffness with good ductility at higher temperatures. The datasheet names no specific part, and no part-level test was read.
- where: Electrical insulation
line: The G22 sheet prints a dielectric strength of 23.0 kV/mm at 2.00 mm and a comparative tracking index of 150 V.
can_do:
- label: Stiffness
value: 4300 MPa
line: The G22 and P22 grades have a tensile modulus of 4300 MPa at 23 °C, and P45 and G45 have 4200 MPa, all from ISO 527-1 datasheet values.
- label: Heat
value: 163 °C deflection temperature
line: G22 has a deflection temperature under load of 163 °C at 1.8 MPa and a melting temperature of 373 °C. Flexural strength falls well before the melt, as the 175 °C value shows.
- label: Yield strength
value: 115 MPa
line: G22 yield stress is 115 MPa at 23 °C in ISO 527-2 tension.
compare: 'Against PEEK, the Shabaev Table 2 gives PEK at 50 % ketone a melting point of 365 °C and glass transition of 152 °C, against 335 °C and 141 °C for PEEK at 33 % ketone. Against PEKK, PEK is lower again: PEKK at 67 % ketone melts at 391 °C with a glass transition of 165 °C. The Victrex HT tensile moduli of 4200 to 4300 MPa and yield stresses of 100 to 115 MPa are datasheet nominal values. No PEEK datasheet value from the same run is used here.'
compare_rows:
- label: Density
benchmark: density
- label: Melting point
benchmark: melting_point
- label: Tensile modulus
benchmark: elastic_modulus
handling:
- Dry before melt processing at 150 °C for 3 h or 120 °C for 5 h, to residual moisture below 0.02 %.
- Use the G22 injection set points for melt and mould temperature; G45 runs hotter, with a 415 °C nozzle.
- Do not use datasheet numbers as design values for printed or extruded parts without test data.
good_for:
- Stiffness at temperature. G22 has a tensile modulus of 4300 MPa at 23 °C and a deflection temperature of 163 °C.
- Injection moulding. G22 and G45 granules have a printed set of processing conditions.
- Electrical insulation. A dielectric strength of 23.0 kV/mm at 2.00 mm.
watch_out:
- High-temperature strength. Flexural stress is 32.0 MPa at 175 °C against 180 MPa at 23 °C.
- No space data. No atomic-oxygen, outgassing, UV or ageing number for PEK was read.
- Grade differences. Elongation at break is 10 % for P22, 15 % for G22 and 20 % for G45 on the Victrex sheets.
verdict: PEK, as Victrex's HT line, is a stiff, heat-tolerant semi-crystalline thermoplastic with datasheet values near 4300 MPa modulus, a glass transition of 160 °C and a melting temperature of 373 °C. The record has no space-ageing data and no hazard classification, so treat any orbital or hazardous use as untested.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| VICTREX HT POLYMER P22 datasheet, unreinforced PEK, coarse powder for extrusion compounding | datasheet | 2026 | 3 values | |
| VICTREX HT POLYMER P45 datasheet, unreinforced PEK, coarse powder for extrusion compounding | datasheet | 2026 | 7 values | |
| VICTREX HT POLYMER G22 datasheet, unreinforced PEK, depth filtered granules for injection moulding | datasheet | 2026 | 24 values | |
| VICTREX HT POLYMER G45 datasheet, unreinforced PEK, depth filtered granules, low flow | datasheet | 2026 | 5 values | |
| Thermal transformation and mechanical properties of high-temperature-resistant matrix based polyetherketones | paper | 2024 | 7 values |