or Plexiglas or Perspex

Trademark names of the organic compound polymethyl methacrylate, a synthetic polymer of methyl methacrylate. Colourless and highly transparent, the solid material has high dimensional stability and good resistance to weathering and shock. It is used in aircraft canopies and windows, in boat windshields, and as a general alternative to glass in many applications. An object made of Lucite has the unusual property of keeping a beam of light reflected within its surfaces and thus carrying the beam around bends and corners; Lucite is therefore used in devices for illuminating interior organs during surgery as well as for ornaments, medallions, and lenses.

Learn more about Lucite with a free trial on Britannica.com.

Methyl methacrylate is an organic compound with the formula CH₂=C(CH₃)CO₂CH₃. This colourless liquid, the methyl ester of methacrylic acid (MAA) is the monomer for the production of the transparent plastic polymethyl methacrylate (PMMA).

Production

Major producers worldwide include Cyro, Arkema, BASF, Dow Chemical, Lucite, Celanese and Rohm and Haas, Mitsubishi Rayon, and Sumitomo. The United States production in 1993 amounted to 600 thousand metric tonnes per annum (mt/a), and the worldwide production in 2005 was estimated at 3.2 million mt/a.

Most producers apply an acetone cyanohydrin (ACH) route, with acetone and hydrogen cyanide as raw materials. The intermediate cyanohydrin is converted with sulfuric acid to a sulfate ester of the methacrylamide, hydrolysis of which gives ammonium bisulfate and MAA. Some Asian producers start with an isobutylene or, equivalently, tert-butanol, which is oxidized to methacrolein, and again oxidized to methacrylic acid. MAA is then esterified with methanol to MMA. Propene can be carbonylated in the presence of acids to isobutyric acid, which undergoes subsequent dehydrogenation.

A newer palladium-catalysed MMA production technology, announced 18th September 2007, uses a homogeneous palladium-phosphine catalyst. Lucite's Alpha process uses ethylene, carbon monoxide, and methanol as raw materials to produce methyl propionate, which is then combined with formaldehyde to produce MMA and water.

Uses

The principal application of methyl methacrylate is the manufacture of polymethyl methacrylate acrylic plastics. Also methyl methacrylate is used for the production of the co-polymer methyl methacrylate-butadiene-styrene (MBS), used as a modifier for PVC.

Methyl methacrylate polymers and co-polymers are used for waterborne coatings, such as latex house paint. It is also used in adhesive formulations.

A modern application is the use in plates that keep light spread evenly across LCD computer and TV screens.

Methyl methacrylate is also used to prepare corrosion casts of anatomical organs, such as coronary arteries of the heart.

See also

• Acrylate polymers
• Acrylates
• Methacrylates
• (Meth)acrylates

References

• Chemical data on Chemicalland
• US Environmental Protection Agency, 1994 data
• Intox Cheminfo data
• SRI Consulting PEP report

External links

• Methacrylate Producers Association (MPA)
• National Pollutant Inventory - Methyl methacrylate fact sheet
• Basic Acrylic Monomer Manufacturers (BAMM)