Physical Properties of Plexiglas, Lucite, Perspex Acrylics

Transparency - In colorless form acrylic plastic is as transparent as the finest optical glass. Its total white light transmittance is 92%, the highest transmittance physically possible of any material.

Breakage Resistance - Acrylic sheet has from 6 to 17 times greater impact resistance than ordinary glass in thicknesses of .125" to .250". When subjected to blows beyond its resistance, acrylic sheet reduces the hazard of injury because it breaks into large relatively dull edged pieces which disperse at low velocity, due to the light weight of the material.

Weather Resistance - The many years of actual outdoor exposure of acrylics in a wide variety of applications, proving its weather resistance, cannot be matched by any other transparent plastic material.

Chemical Resistance - Acrylic plastic has excellent resistance to most chemicals, including solutions of inorganic alkalis and acids such as ammonia and sulfuric acid, and aliphatic hydrocarbons such as hexane, octane and VM&P naphtha. It is attacked by the following chemicals:

Gasoline

Chlorinated hydrocarbons such as methylene chloride, a solvent cement widely used, and carbon tetrachloride.

Aromatic solvents such as turpentine, benzene, and toluene.

Ethyl and methyl alcohol.

Organic acids such as acetic acid, phenols, and lysol.

Lacquer thinners and other esters, ketones, and ethers.

Light Weight - Acrylic sheet is less than half as heavy as glass: it is 43% as heavy as aluminum and 70% as heavy as magnesium.

Dimensional Stability - Acrylic sheet is notable for its freedom from shrinking and deterioration through long periods of use. Many drawing instruments requiring exact dimensional stability have been fabricated from Plexiglas.

Combustibility - Acrylic sheet is a combustible thermoplastic and should be treated as an ordinary combustible material such as wood. The self ignition temperature (spontaneous combustion) of acrylic is between 850 degree F and 869 degree F. The temperature at which the material will ignite in the presence of a flame is between 550 degree F and 570 degree F. While the ignition temperatures of acrylic are higher than that of most woods, it burns vigorously and generates heat rapidly when involved in fire. The primary products of acrylic combustion are carbon monoxide and carbon dioxide, however, burning acrylic plastic does not produce either excessive quantities of smoke or gasses more toxic than those produced by burning wood or paper. Observe fire precautions appropriate for comparable forms of wood and paper products.

Heat Resistance - The maximum "continuous service temperature" of acrylic is between 180 degrees F and 200 degrees F depending on the particular use. This means that while the material can withstand higher temperatures for very short periods of time, it will soften and lose its form or shape if subjected to these higher temperatures for any period of time. While acrylics respond to heat, they are not affected by cold, and will not become cracked or brittle in cold weather.

Electrical Properties - Acrylic plastics are affected only a minor degree by weathering or moisture. Its surface resistivity is higher than that of most other materials, and makes an ideal insulator.

U-Factor - heat transfer through .187" thick acrylic is approximately 20% less than through equivalent thickness of glass.

(0.187" acrylic = 1.09 BTU's/hr./sq. ft./ degree F with 15 MPH and 0 degree F air on one side and 0 MPH and 70 degree F air on the other. 0.187" Glass = 1.23 BTU's/hr./sq. ft./degree F under the same conditions).