PMMA is a mid-priced amorphous plastic with exceptional transparency. It is often called Acrylic.
Why choose it?
- Glass-like transparency. PMMA is commonly used in different types of lenses.
- Exceptionally good UV resistance.
- Scratch resistance due to high surface hardness.
Why not choose it?
- Poor thermal resistance. PMMP becomes very soft at temperatures as low as 70°C.
- Fragility. Thin-walled PMMA components are sensitive to impacts.
- Boat windows
- Car lights
PMMI is a very similar material with excellent transparency. The main difference is the improved thermal resistance. PMMI is better than PMMA in, for example, car headlight optics, in which the temperature might rise up to 150°C.