Thermoplastic comparison
PETG (glycol-modified PET) vs Polystyrene (GPPS)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
| Property | PETG (glycol-modified PET) | Polystyrene (GPPS) | Difference |
|---|---|---|---|
| Density | 1.3 g/cm³ | 1.05 g/cm³ | PETG (glycol-modified PET) — 24% higher |
| Young's modulus E | 2.2 GPa | 3.2 GPa | Polystyrene (GPPS) — 45% higher |
| Tensile strength | 53 MPa | 46 MPa | PETG (glycol-modified PET) — 15% higher |
| Glass transition Tg | 81 °C | 100 °C | Polystyrene (GPPS) — 19 °C higher |
Where these numbers come from
- MakeItFrom.com materials database — typical grade values
- Callister & Rethwisch, Materials Science and Engineering, 10th ed.
Typical room-temperature values for learning and preliminary design; grades vary widely and a supplier datasheet always overrides a textbook figure. Confirm against the datasheet before design work.