Borosilicate Glass vs. PEI
Borosilicate glass and PEI belong to fundamentally different material chemistries. Borosilicate glass is a ceramic material, while PEI is polymeric. Therefore, their performance will be even more dissimilar than would be suggested by the difference in properties. There are 18 material properties with values for both materials. Properties with values for just one material (21, in this case) are not shown.
For each property being compared, the top bar is borosilicate glass and the bottom bar is PEI.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 2000 | |
| 140 to 180 |
| Elastic (Young's, Tensile) Modulus, GPa | 67 to 80 | |
| 3.4 to 5.6 |
| Flexural Strength, MPa | 34 to 69 | |
| 140 to 210 |
| Tensile Strength: Ultimate (UTS), MPa | 280 | |
| 110 to 160 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 360 | |
| 170 |
| Specific Heat Capacity, J/kg-K | 830 | |
| 1050 to 1220 |
| Thermal Conductivity, W/m-K | 1.2 | |
| 0.18 to 0.23 |
| Thermal Expansion, µm/m-K | 3.3 to 5.1 | |
| 20 to 53 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 5.4 | |
| 3.2 to 3.7 |
| Dielectric Strength (Breakdown Potential), kV/mm | 5.0 to 34 | |
| 30 to 33 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 9.0 to 12 | |
| 14 to 15 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.2 to 2.6 | |
| 1.3 to 1.5 |
Common Calculations
| Stiffness to Weight: Axial, points | 15 to 17 | |
| 1.5 to 2.1 |
| Stiffness to Weight: Bending, points | 55 to 61 | |
| 39 |
| Strength to Weight: Axial, points | 30 to 35 | |
| 24 to 30 |
| Strength to Weight: Bending, points | 36 to 43 | |
| 40 to 44 |
| Thermal Diffusivity, mm2/s | 0.54 to 0.63 | |
| 0.11 to 0.14 |
| Thermal Shock Resistance, points | 50 to 91 | |
| 44 to 100 |