Polymethylmetakrylat

Polymethylmetakrylat, commonly known as polymethyl methacrylate (PMMA), is a transparent thermoplastic polymer produced from the methyl methacrylate monomer. It is widely sold under trade names such as Plexiglas, Lucite, and Acrylite. PMMA offers exceptional optical clarity and high light transmittance, with a refractive index around 1.49 and a light transmittance exceeding 92% in thin gauges.

Properties include good weather resistance and UV stability when stabilized, resistance to many chemicals but solubility in certain solvents like ketones and esters. The surface can be scratched, though hard coatings can improve scratch resistance. PMMA maintains rigidity over a wide temperature range, with a glass transition around 105°C. It is a stiff, lightweight material that remains relatively stable under ordinary environmental conditions.

Processing involves it being a thermoplastic that can be cast, extruded, injection molded, or thermoformed. PMMA is produced by polymerization of methyl methacrylate via free-radical mechanisms; polymerization methods include bulk, solution, and suspension polymerization. It can be toughened by impact modifiers or blended with other materials. Recyclability is possible by mechanical recycling and reprocessing; scrap may be re-melted for re-forming.

Applications include glazing in architecture and automotive lighting, lenses, signage, and aquariums. Medical uses include bone cement and denture bases, while dental prostheses often utilize PMMA resin. Safety considerations note that the monomer methyl methacrylate is toxic and irritant, and proper handling and complete curing are essential. PMMA is generally inert and non-biodegradable, with recycling challenges due to contamination and material properties.