Thermoplastic comparison
Polyethylene, high-density (HDPE) vs PBT (polybutylene terephthalate)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
| Property | Polyethylene, high-density (HDPE) | PBT (polybutylene terephthalate) | Difference |
|---|---|---|---|
| Density | 0.95 g/cm³ | 1.31 g/cm³ | PBT (polybutylene terephthalate) — 38% higher |
| Young's modulus E | 1 GPa | 2.6 GPa | PBT (polybutylene terephthalate) — 2.6× higher |
| Tensile strength | 27 MPa | 55 MPa | PBT (polybutylene terephthalate) — 2.0× higher |
| Glass transition Tg | -120 °C | 45 °C | PBT (polybutylene terephthalate) — 165 °C higher |
| Melting point Tm | 131 °C | 225 °C | PBT (polybutylene terephthalate) — 94 °C higher |
Where these numbers come from
- Callister & Rethwisch, Materials Science and Engineering, 10th ed.
- CAMPUS plastics database — typical grade datasheet values (campusplastics.com)
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.