PS vs. PEI
Both PS and PEI are thermoplastics. There are 23 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.
For each property being compared, the top bar is PS and the bottom bar is PEI.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 1.9 to 2.9 | |
| 3.4 to 5.6 |
| Elongation at Break, % | 1.8 to 40 | |
| 3.0 to 34 |
| Flexural Strength, MPa | 62 to 80 | |
| 140 to 210 |
| Impact Strength: Notched Izod, J/m | 19 to 45 | |
| 55 to 110 |
| Tensile Strength: Ultimate (UTS), MPa | 32 to 44 | |
| 110 to 160 |
Thermal Properties
| Glass Transition Temperature, °C | 100 | |
| 210 |
| Maximum Temperature: Autoignition, °C | 360 to 420 | |
| 530 |
| Maximum Temperature: Decomposition, °C | 320 to 330 | |
| 530 |
| Maximum Temperature: Mechanical, °C | 70 | |
| 170 |
| Specific Heat Capacity, J/kg-K | 1250 to 1400 | |
| 1050 to 1220 |
| Thermal Conductivity, W/m-K | 0.14 to 0.22 | |
| 0.18 to 0.23 |
| Thermal Expansion, µm/m-K | 80 to 98 | |
| 20 to 53 |
Electrical Properties
| Dielectric Strength (Breakdown Potential), kV/mm | 18 to 20 | |
| 30 to 33 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 14 to 15 | |
| 14 to 15 |
Otherwise Unclassified Properties
| Density, g/cm3 | 1.0 | |
| 1.3 to 1.5 |
| Limiting Oxygen Index (LOI), % | 18 | |
| 47 to 50 |
| Water Absorption After 24 Hours, % | 0.040 to 0.080 | |
| 0.17 to 0.25 |
Common Calculations
| Stiffness to Weight: Axial, points | 1.0 to 1.5 | |
| 1.5 to 2.1 |
| Stiffness to Weight: Bending, points | 40 to 45 | |
| 39 |
| Strength to Weight: Axial, points | 8.5 to 12 | |
| 24 to 30 |
| Strength to Weight: Bending, points | 22 to 26 | |
| 40 to 44 |
| Thermal Diffusivity, mm2/s | 0.11 to 0.15 | |
| 0.11 to 0.14 |
| Thermal Shock Resistance, points | 11 to 15 | |
| 44 to 100 |