Thermoplastic comparison
Polycarbonate (PC) vs Acrylic (PMMA)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
Which to choose
Both are transparent, and the choice is almost always impact versus surface. Polycarbonate is effectively unbreakable by hand but scratches easily and yellows in sunlight without a coating; acrylic is harder, more scratch-resistant and holds its clarity outdoors, but it cracks. PC for guards and glazing; PMMA for lenses, signage and display.
| Property | Polycarbonate (PC) | Acrylic (PMMA) | Difference |
|---|---|---|---|
| Density | 1.2 g/cm³ | 1.19 g/cm³ | Polycarbonate (PC) — 1% higher |
| Young's modulus E | 2.4 GPa | 3.1 GPa | Acrylic (PMMA) — 29% higher |
| Tensile strength | 65 MPa | 72 MPa | Acrylic (PMMA) — 11% higher |
| Glass transition Tg | 147 °C | 105 °C | Polycarbonate (PC) — 42 °C higher |
Where these numbers come from
- 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.