PEI vs. Thermoset PI
PEI belongs to the thermoplastics classification, while thermoset PI belongs to the thermoset plastics. There are 24 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is PEI and the bottom bar is thermoset PI.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 140 to 180 | |
| 120 to 210 |
| Elongation at Break, % | 3.0 to 34 | |
| 2.0 to 5.9 |
| Flexural Modulus, GPa | 3.4 to 5.9 | |
| 3.1 to 4.8 |
| Flexural Strength, MPa | 140 to 210 | |
| 60 to 100 |
| Impact Strength: Notched Izod, J/m | 55 to 110 | |
| 21 to 43 |
| Tensile Strength: Ultimate (UTS), MPa | 110 to 160 | |
| 37 to 81 |
Thermal Properties
| Glass Transition Temperature, °C | 210 | |
| 360 |
| Heat Deflection Temperature At 1.82 MPa (264 psi), °C | 200 to 210 | |
| 370 |
| Maximum Temperature: Autoignition, °C | 530 | |
| 380 |
| Maximum Temperature: Decomposition, °C | 530 | |
| 330 |
| Maximum Temperature: Mechanical, °C | 170 | |
| 260 |
| Specific Heat Capacity, J/kg-K | 1050 to 1220 | |
| 1130 |
| Thermal Conductivity, W/m-K | 0.18 to 0.23 | |
| 0.29 to 1.7 |
| Thermal Expansion, µm/m-K | 20 to 53 | |
| 38 to 54 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 3.2 to 3.7 | |
| 3.1 |
| Dielectric Strength (Breakdown Potential), kV/mm | 30 to 33 | |
| 20 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 14 to 15 | |
| 15 |
Otherwise Unclassified Properties
| Density, g/cm3 | 1.3 to 1.5 | |
| 1.4 to 1.6 |
| Limiting Oxygen Index (LOI), % | 47 to 50 | |
| 40 |
| Water Absorption After 24 Hours, % | 0.17 to 0.25 | |
| 0.14 to 0.24 |
| Water Absorption At Saturation, % | 0.9 to 1.3 | |
| 3.6 |
Common Calculations
| Strength to Weight: Axial, points | 24 to 30 | |
| 6.5 to 16 |
| Strength to Weight: Bending, points | 40 to 44 | |
| 16 to 30 |
| Thermal Diffusivity, mm2/s | 0.11 to 0.14 | |
| 0.18 to 0.95 |