PEEK vs. Thermoset PI
PEEK belongs to the thermoplastics classification, while thermoset PI belongs to the thermoset plastics. There are 22 material properties with values for both materials. Properties with values for just one material (9, in this case) are not shown.
For each property being compared, the top bar is PEEK and the bottom bar is thermoset PI.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 120 to 300 | |
| 120 to 210 |
| Elongation at Break, % | 1.6 to 43 | |
| 2.0 to 5.9 |
| Flexural Modulus, GPa | 3.8 to 19 | |
| 3.1 to 4.8 |
| Flexural Strength, MPa | 150 to 330 | |
| 60 to 100 |
| Impact Strength: Notched Izod, J/m | 78 to 120 | |
| 21 to 43 |
| Tensile Strength: Ultimate (UTS), MPa | 97 to 200 | |
| 37 to 81 |
Thermal Properties
| Glass Transition Temperature, °C | 240 | |
| 360 |
| Heat Deflection Temperature At 1.82 MPa (264 psi), °C | 160 to 300 | |
| 370 |
| Maximum Temperature: Autoignition, °C | 600 | |
| 380 |
| Maximum Temperature: Decomposition, °C | 570 | |
| 330 |
| Maximum Temperature: Mechanical, °C | 330 | |
| 260 |
| Specific Heat Capacity, J/kg-K | 1390 to 1700 | |
| 1130 |
| Thermal Conductivity, W/m-K | 0.25 to 0.93 | |
| 0.29 to 1.7 |
| Thermal Expansion, µm/m-K | 15 to 52 | |
| 38 to 54 |
Electrical Properties
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 3.0 to 14 | |
| 15 |
Otherwise Unclassified Properties
| Density, g/cm3 | 1.3 to 1.5 | |
| 1.4 to 1.6 |
| Limiting Oxygen Index (LOI), % | 38 | |
| 40 |
| Water Absorption After 24 Hours, % | 0.060 to 0.3 | |
| 0.14 to 0.24 |
| Water Absorption At Saturation, % | 0.22 to 0.5 | |
| 3.6 |
Common Calculations
| Strength to Weight: Axial, points | 20 to 41 | |
| 6.5 to 16 |
| Strength to Weight: Bending, points | 36 to 55 | |
| 16 to 30 |
| Thermal Diffusivity, mm2/s | 0.1 to 0.51 | |
| 0.18 to 0.95 |