Acrylics (PMMA): Characteristics
Clearer than glass at half the weight
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.PMMA is valued for clarity, weathering and surface hardness. Cast sheet has higher molecular weight and better chemical resistance than extruded sheet. Moulding grades are chosen by flow and heat resistance.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Light transmission | about 92% (indicative) | Clearer than glass and polycarbonate | typical datasheet values (indicative) |
| Density | about 1.18-1.19 g/cm3 (indicative) | About half the weight of glass | typical datasheet values (indicative) |
| Vicat softening point | about 100-115 C (indicative) | Limits use near heat; heat-resistant grades exist | typical datasheet values (indicative) |
| Pencil hardness | about 2H-3H (indicative) | More scratch-resistant than PC | typical datasheet values (indicative) |
Commercial grades
- cell-cast sheet
- continuous-cast and extruded sheet
- general moulding pellets
- heat-resistant moulding
- impact-modified
- optical light-guide grades
- medical and dental grades
- recycled (r-PMMA) from depolymerisation