Thermoplastic comparison
PEI (Ultem) 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 | PEI (Ultem) | PHB (polyhydroxybutyrate, a PHA) | Difference |
|---|---|---|---|
| Density | 1.27 g/cm³ | 1.25 g/cm³ | PEI (Ultem) — 2% higher |
| Young's modulus E | 3.2 GPa | 3.5 GPa | PHB (polyhydroxybutyrate, a PHA) — 9% higher |
| Tensile strength | 105 MPa | 40 MPa | PEI (Ultem) — 2.6× higher |
| Glass transition Tg | 217 °C | 4 °C | PEI (Ultem) — 213 °C higher |
Where these numbers come from
- CAMPUS plastics database — typical grade datasheet values (campusplastics.com)
- 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.