Polymethyl Methacrylate PMMA
Polymethyl Methacrylate (PMMA)
a thermoplastic linear polymer of methyl methacrylate:
The primary commercial product is known as organic glass.
PMMA, with a molecular weight of up to 2 × 106, is exceptionally transparent, with high permeability for visible and ultraviolet light; it also has good physical, mechanical, and electrical insulation properties. It is weatherproof and resistant to dilute acids and alkalies, water, alcohols, fats, and mineral oils. PMMA exhibits no harmful physiological effect and is resistant to biological agents. It softens at temperatures slightly higher than 120°C and is readily workable.
PMMA is produced industrially by free-radical polymerization of the monomer, usually in bulk or suspension, and less frequently in an emulsion or solution. It is generally produced as sheets and granulated materials, which undergo subsequent injection molding or extrusion. It is used in transportation machine building, the aircraft industry, illumination engineering, construction and architecture, and instrument making, as well as in the preparation of billboards, advertisements, and household goods.
Suspension PMMA is produced in the USSR (various trademarks), the USA (Lucite), Great Britain (Diakon), the Federal Republic of Germany (Plexigum), and Italy (Vedril).
(For trade names of block PMMA manufactured in sheet form, see ORGANIC GLASS.)
In 1973, world production of polymethyl methacrylate was about 750,000 tons.
REFERENCESSee references under .
E. M. LUKINA