Brittleness Temperature

As the temperature drops, polymers become brittle.  When a plastic is chosen for operation at low temperatures, its reliability should be checked.  The brittleness temperature should be lower than the normal operating temperature of the application. 

Brittleness Test
The brittleness test is done by placing a number of specimens of a polymer in a bath.  The temperature is gradually lowered.  The specimens are continually impacted with a hammer at a speed of 2000 mm/s. 

At a specific temperature, the specimens will start cracking.  The temperature at which half of the specimens crack is called the Brittleness Temperature of the polymer.