Polymethylmethacrylaat

Polymethylmethacrylaat, commonly abbreviated PMMA, is a synthetic transparent thermoplastic polymer in the acrylic family. It is produced by the polymerization of the methyl methacrylate monomer and is marketed under trade names such as Plexiglas, Lucite, and Perspex. The material is optically clear, has a high surface gloss, and exhibits good weathering resistance when stabilized against UV light.

PMMA is a rigid, lightweight material with a density of about 1.18 g/cm3 and a refractive index around 1.49. It is amorphous and has a glass transition temperature near 105 °C. PMMA remains transparent over a broad temperature range and is relatively resistant to many chemicals; however, prolonged UV exposure can cause yellowing without stabilizers. It provides good electrical insulation and can be formulated in transparent sheets, tubes, and rods.

PMMA is produced mainly by free-radical polymerization of methyl methacrylate, using bulk, suspension, or emulsion polymerization. The process yields an amorphous thermoplastic that can be molded by extrusion, casting, or thermoforming.

Applications include glazing for architectural and automotive uses, display cases, ophthalmic lenses, medical devices, dental materials, and signs. It is also used in signage, light guides, and certain consumer products where clarity and impact resistance are valued.

Environmental and safety considerations: PMMA is relatively inert but not biodegradable. When processed as dust or scrap, it can irritate skin, eyes, and lungs; standard industrial hygiene applies. Recycling is possible but not universally available; mechanical recycling and some chemical recycling methods exist to recover monomer or remelt PMMA for reuse.