26-03-2014, 04:57 PM
Poly(methyl methacrylate) (PMMA)
[attachment=60498]
History
The first acrylic acid was created in 1843. Methacrylic acid, derived from acrylic acid, was formulated in 1865. The reaction between methacrylic acid and methanol results in the ester methyl methacrylate.
The German chemists Fittig and Paul discovered in 1877 the polymerization process that turns methyl methacrylate into polymethyl methacrylate.
In 1933 the German chemist Otto Röhm patented and registered the brand name PLEXIGLAS. In 1936 the first commercially viable production of acrylic safety glass began.
During World War II acrylic glass was used for submarine periscopes, and windshields, canopies, and gun turrets for airplanes.
Preparation
PMMA is routinely produced by emulsion polymerization, solution polymerization and bulk polymerization.
Generally radical initiation is used (including living polymerization methods), but anionic polymerization of PMMA can also be performed.
Polymerisation
PMMA for molding or extrusion is made by bulk or suspension polymerisation.
The production of cast sheets, rods, and tubes is carried out by bulk polymerisation, starting in most cases with a syrup of partially polymerised methyl methacrylate.
Physical properties
PMMA is strong and lightweight.
It has a density of 1.150–1.190 g/cm3 about less than half that of glass and similar other plastics.
It also has good impact strength, higher than both glass and polystyrene; however, PMMA's impact strength is still significantly lower than polycarbonate and some engineered polymers.
PMMA ignites at 460 °C (860 °F) and burns, forming carbon dioxide, water, carbon monoxide and low molecular weight compounds, including formaldehyde.
Applications
PMMA is used as a shield to stop beta radiation emitted from radioisotopes.
PMMA was used in laserdisc optical media and in 3D optical data storage
PMMA, in a purified form, is used as the matrix in dye-doped solid-state gain media for solid state dye lasers.
Artificial fingernails are made of acrylic.
Small strips of PMMA are used as dosimeter devices during the Gamma Irradiation process.
[attachment=60498]
History
The first acrylic acid was created in 1843. Methacrylic acid, derived from acrylic acid, was formulated in 1865. The reaction between methacrylic acid and methanol results in the ester methyl methacrylate.
The German chemists Fittig and Paul discovered in 1877 the polymerization process that turns methyl methacrylate into polymethyl methacrylate.
In 1933 the German chemist Otto Röhm patented and registered the brand name PLEXIGLAS. In 1936 the first commercially viable production of acrylic safety glass began.
During World War II acrylic glass was used for submarine periscopes, and windshields, canopies, and gun turrets for airplanes.
Preparation
PMMA is routinely produced by emulsion polymerization, solution polymerization and bulk polymerization.
Generally radical initiation is used (including living polymerization methods), but anionic polymerization of PMMA can also be performed.
Polymerisation
PMMA for molding or extrusion is made by bulk or suspension polymerisation.
The production of cast sheets, rods, and tubes is carried out by bulk polymerisation, starting in most cases with a syrup of partially polymerised methyl methacrylate.
Physical properties
PMMA is strong and lightweight.
It has a density of 1.150–1.190 g/cm3 about less than half that of glass and similar other plastics.
It also has good impact strength, higher than both glass and polystyrene; however, PMMA's impact strength is still significantly lower than polycarbonate and some engineered polymers.
PMMA ignites at 460 °C (860 °F) and burns, forming carbon dioxide, water, carbon monoxide and low molecular weight compounds, including formaldehyde.
Applications
PMMA is used as a shield to stop beta radiation emitted from radioisotopes.
PMMA was used in laserdisc optical media and in 3D optical data storage
PMMA, in a purified form, is used as the matrix in dye-doped solid-state gain media for solid state dye lasers.
Artificial fingernails are made of acrylic.
Small strips of PMMA are used as dosimeter devices during the Gamma Irradiation process.