PET vs. PBT
Both PET and PBT are thermoplastics. There are 15 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.
For each property being compared, the top bar is PET and the bottom bar is PBT.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 3.5 to 11 | |
| 2.7 to 8.7 |
| Elongation at Break, % | 2.5 to 70 | |
| 2.5 to 43 |
| Flexural Modulus, GPa | 8.3 to 14 | |
| 2.6 to 9.1 |
| Tensile Strength: Ultimate (UTS), MPa | 60 to 140 | |
| 58 to 140 |
Thermal Properties
| Glass Transition Temperature, °C | 70 | |
| 40 |
| Maximum Temperature: Autoignition, °C | 410 | |
| 380 |
| Maximum Temperature: Decomposition, °C | 390 | |
| 380 |
| Melting Onset (Solidus), °C | 260 | |
| 230 |
| Specific Heat Capacity, J/kg-K | 1000 to 1150 | |
| 1040 to 1200 |
Otherwise Unclassified Properties
| Density, g/cm3 | 1.4 to 1.6 | |
| 1.3 to 1.5 |
| Limiting Oxygen Index (LOI), % | 21 | |
| 20 |
Common Calculations
| Stiffness to Weight: Axial, points | 1.2 to 4.4 | |
| 1.1 to 3.2 |
| Stiffness to Weight: Bending, points | 32 to 54 | |
| 35 to 45 |
| Strength to Weight: Axial, points | 12 to 27 | |
| 12 to 25 |
| Strength to Weight: Bending, points | 25 to 41 | |
| 25 to 38 |