PMMA vs Soda-lime glass
PMMA and Soda-lime glass are genuine alternatives to one another — a choice somebody actually makes — and differ on 1 measured property, density most clearly.
PMMA vs Soda-lime glass
PMMA
Clearer than glass and it shatters into blunt pieces — the aquarium wall, the aircraft canopy, the signage and the museum case.
Soda-lime glass
The commonest glass — silica with soda to lower its melting point and lime to stop it dissolving in water.
| Property | PMMA | Soda-lime glass |
|---|---|---|
| Crystal system Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | amorphous |
| Density | 1.17–1.2 g/cm³ | 2.44–2.55 g/cm³ higher |
| Refractive index Only one of the two has a figure we can stand behind, so there is nothing to compare. | 1.49 | Not known |
| Tensile strength Only one of the two has a figure we can stand behind, so there is nothing to compare. | 65–75 MPa | Not known |
| Young's modulus Only one of the two has a figure we can stand behind, so there is nothing to compare. | 2.4–3.3 GPa | Not known |
Choosing between them
PMMA is recorded as a substitute for Soda-lime glass — lighter, easier to work.
What it gives up: Scratches from ordinary cleaning, and softens near 100 °C — glass keeps its surface for a century and acrylic does not.
In this application, on the evidence cited above.