Thermoplastic comparison
PET vs PHB (polyhydroxybutyrate, a PHA)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
| Property | PET | PHB (polyhydroxybutyrate, a PHA) | Difference |
|---|---|---|---|
| Density | 1.37 g/cm³ | 1.25 g/cm³ | PET — 10% higher |
| Young's modulus E | 2.9 GPa | 3.5 GPa | PHB (polyhydroxybutyrate, a PHA) — 21% higher |
| Tensile strength | 60 MPa | 40 MPa | PET — 50% higher |
| Glass transition Tg | 76 °C | 4 °C | PET — 72 °C higher |
| Melting point Tm | 255 °C | 177 °C | PET — 78 °C higher |
Where these numbers come from
- Callister & Rethwisch, Materials Science and Engineering, 10th ed.
- Sudesh, Abe & Doi, Prog. Polym. Sci. 25 (2000) 1503–1555 — PHA structure & properties review
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.