PMMA (cast)

Polymethyl-methacrylate (PMMA) is a transparent amorphous polymer. PMMA is well known under many other (brand)names such as acrylic, acrylic glass, Plexiglas or Perspex. It is very well suited to replace glass where a higher (impact) strength, lower weight and/or easier formability are desired. Important applications are in windows for aircrafts, safety glass, lighting armatures, car lighting and lenses.
Because the weathering resistance of PMMA is very good, it is especially suitable for outdoor applications with a long lifespan.

Specific properties
Density: ca. 1.19 g/cm3.

Mechanical properties: High Young's Modulus, around 3 GPa, strength around 70 MPa. As an injection mouldable material it is quite brittle, but impact resistant types with a lower Young's Modulus and strength are available.
As sheet material it can be much more impact resistant.

Thermal properties: Tg ca. 105 °C, HDT around 80°C.

Chemical resistance: low resistance to organic liquids. Good UV and weathering resistance.

Colourless and transparent with a very high light transmission. Glossy surface. Can be coloured with transparent pigments.
The refractive index is 1.49.

Can be injection moulded and extruded. In a different type of process, casting from a liquid precursor, large objects and thick sheets can be made without shrinkage and stress problems.
PMMA can be glued with certain solvents.

Automotive industry: lighting, such as coloured rear lights
Aerospace: windows in planes and helicopters
Outdoor applications: street lighting, road signs, traffic lights,
Protection: transparent protecting plates, motorcycle helmet sight,
safety goggles and face guards
Medical: contact lenses
Optical: lenses for phones, camera’s and photocopiers
Other items: aquariums from small to extremely large,
windows and cupolas for submarines

Poly(methyl methacrylate)

Young's modulus 2855 MPa
Tensile strength 75 MPa
Elongation 4.5 %
Compressive strength 117.5 MPa
Bending strength 110 MPa
Hardness 90 Rockwell
Impact strength 0.24 J/cm
Yield strength 0 MPa
Thermal expansion 70 E-6/K
Thermal conductivity 0.2085 W/m*K
Specific heat 1466 J/kg*K
Vicat 115 °C
Melting temperature Amorphou °C
Glass temperature 105 °C
Minimum service temperature -40 °C
Maximum service temperature 90 °C
Density 1185 kg/m3
Resistivity 1E+19 Ohm*mm2/m
Breakdown potential 23.85 kV/mm
Dielectric loss factor 0.055
Friction coefficient 0.53
Refraction index 1.492
Shrinkage 0.55 %
Water absorption 0.3 %