Borosilicate Glass vs. PBI
Borosilicate glass and PBI belong to fundamentally different material chemistries. Borosilicate glass is a ceramic material, while PBI is polymeric. Therefore, their performance will be even more dissimilar than would be suggested by the difference in properties. There are 19 material properties with values for both materials. Properties with values for just one material (18, in this case) are not shown.
For each property being compared, the top bar is borosilicate glass and the bottom bar is PBI.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 2000 | |
| 350 |
| Elastic (Young's, Tensile) Modulus, GPa | 67 to 80 | |
| 5.9 |
| Flexural Strength, MPa | 34 to 69 | |
| 220 |
| Tensile Strength: Ultimate (UTS), MPa | 280 | |
| 160 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 360 | |
| 340 |
| Specific Heat Capacity, J/kg-K | 830 | |
| 930 |
| Thermal Conductivity, W/m-K | 1.2 | |
| 0.41 |
| Thermal Expansion, µm/m-K | 3.3 to 5.1 | |
| 23 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 Hz | 4.8 to 5.5 | |
| 3.4 |
| Dielectric Constant (Relative Permittivity) At 1 MHz | 5.4 | |
| 3.8 |
| Dielectric Strength (Breakdown Potential), kV/mm | 5.0 to 34 | |
| 23 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 9.0 to 12 | |
| 13 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.2 to 2.6 | |
| 1.3 |
Common Calculations
| Stiffness to Weight: Axial, points | 15 to 17 | |
| 2.5 |
| Stiffness to Weight: Bending, points | 55 to 61 | |
| 46 |
| Strength to Weight: Axial, points | 30 to 35 | |
| 34 |
| Strength to Weight: Bending, points | 36 to 43 | |
| 50 |
| Thermal Diffusivity, mm2/s | 0.54 to 0.63 | |
| 0.34 |
| Thermal Shock Resistance, points | 50 to 91 | |
| 84 |