Borosilicate Glass vs. Thermoset PI
Borosilicate glass and thermoset PI belong to fundamentally different material chemistries. Borosilicate glass is a ceramic material, while thermoset PI is polymeric. Therefore, their performance will be even more dissimilar than would be suggested by the difference in properties. There are 14 material properties with values for both materials. Properties with values for just one material (24, in this case) are not shown.
For each property being compared, the top bar is borosilicate glass and the bottom bar is thermoset PI.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 2000 | |
| 120 to 210 |
| Flexural Strength, MPa | 34 to 69 | |
| 60 to 100 |
| Tensile Strength: Ultimate (UTS), MPa | 280 | |
| 37 to 81 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 360 | |
| 260 |
| Specific Heat Capacity, J/kg-K | 830 | |
| 1130 |
| Thermal Conductivity, W/m-K | 1.2 | |
| 0.29 to 1.7 |
| Thermal Expansion, µm/m-K | 3.3 to 5.1 | |
| 38 to 54 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 5.4 | |
| 3.1 |
| Dielectric Strength (Breakdown Potential), kV/mm | 5.0 to 34 | |
| 20 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 9.0 to 12 | |
| 15 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.2 to 2.6 | |
| 1.4 to 1.6 |
Common Calculations
| Strength to Weight: Axial, points | 30 to 35 | |
| 6.5 to 16 |
| Strength to Weight: Bending, points | 36 to 43 | |
| 16 to 30 |
| Thermal Diffusivity, mm2/s | 0.54 to 0.63 | |
| 0.18 to 0.95 |