Thermoplastic comparison
PBT (polybutylene terephthalate) vs Polypropylene (PP)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
| Property | PBT (polybutylene terephthalate) | Polypropylene (PP) | Difference |
|---|---|---|---|
| Density | 1.31 g/cm³ | 0.905 g/cm³ | PBT (polybutylene terephthalate) — 45% higher |
| Young's modulus E | 2.6 GPa | 1.4 GPa | PBT (polybutylene terephthalate) — 86% higher |
| Tensile strength | 55 MPa | 34 MPa | PBT (polybutylene terephthalate) — 62% higher |
| Glass transition Tg | 45 °C | -10 °C | PBT (polybutylene terephthalate) — 55 °C higher |
| Melting point Tm | 225 °C | 165 °C | PBT (polybutylene terephthalate) — 60 °C higher |
Where these numbers come from
- CAMPUS plastics database — typical grade datasheet values (campusplastics.com)
- 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.