Properties of PLEXIGLAS®

PLEXIGLAS^® sheets expand due to heat and/or humidity and contract upon exposure to cold and/or dryness. The sheet lengths must be dimensioned such that the sheets cannot slide out of the upper clamping or connecting bar in the cold. On the other hand, the material must be allowed to expand freely in hot weather to exclude damage, e.g. due to buckling.

With reference to an installation temperature of 10 degrees Celsius (°C) for example, the sheets contract in the cold season by up to 2.5 millimeters per meter (mm/m). On the other hand, a general allowance should be included for expansion due to heat and humidity.

For PLEXIGLAS^® Standard, the expansion allowance is 5 mm/m. 
For PLEXIGLAS RESIST^®, the expansion allowance is 6 mm/m.

Mechanical properties / Standard / Value 

Density / ISO 1183 / 1.19 g/cm3 
Tensile strength / ISO 527-2/1B/5 / 80 MPa 
Elongation at break / ISO 527-2/1B/5 / 5.5% 
Modulus of elasticity / ISO 527-2/1B/1 / 3300 MPa 
Flexural strength / ISO 178 / 115 MPa 
Compressive yield stress / ISO 604 / 110 MPa 
Shear modulus / ISO 537 / 1700 MPa 
Impact strength / ISO 179/1fu / 15 kJ/m² 
Notched impact strength / ISO 180/1 A / 1.6 kJ/m² 
Admissible material stress / - / 5 - 10 MPa 
Poisson’s ratio / ISO 527-1 / 0.37 
Ball indentation hardness / ISO 2039-1 / 175 MPa 
Scratch resistance / ISO 9352 / 20 - 30% haze 
Minimum cold-bending radius / - / 330 x sheet thickness

see also Product Description PLEXIGLAS^® GS/PLEXIGLAS^® XT

PLEXIGLAS^® has a density of approx. 1.20 grams per cubic centimeter (g/cm³). The area weight per square meter (m²) is calculated as follows:

Area weight PLEXIGLAS^® solid sheets = square meter x sheet thickness in millimeters x density

PLEXIGLAS^® with a sheet thickness of 10 mm therefore weighs 15 kilograms per square meter.

PLEXIGLAS^® absorbs about 1.2 percent (%) water in humid ambient air and about 2% when stored in water. That means a one-meter-long (m) sheet of PLEXIGLAS^® expands by about 1 to 2 mm, depending on how it is stored. The increase in volume due to water absorption is taken into account in the recommended expansion allowance of about 5 mm/m sheet length for PLEXIGLAS^®. The permeation coefficient for water vapor (g cm / cm2 h Pa) is 2.3 x 10^-10.

Even at extreme temperatures of - 40 degrees Celsius (°C), PLEXIGLAS^® shows no self-destruction. The tensile strength increases from 80 megapascals (MPa) at 23°C to 110 MPa at - 40°C, which suggests an increase in brittleness.

PLEXIGLAS^® is permeable to gas. The permeation coefficient (g cm / cm2 h Pa ) for the following media is:

Water vapor 2.3 x 10^-10

Nitrogen (N2) 4.5 x 10^-15

Oxygen (O2) 2.0 x 10^-14

Carbon dioxide (CO2) 1.1 x 10^-13

Air 8.3 x 10^-15

PLEXIGLAS^® shows good resistance to inorganic substances, acids and alkalis at low concentrations, salts and salt solutions.

PLEXIGLAS^® is not resistant to organic compounds, chlorinated hydrocarbons, ketones and esters.