Elastomers are rigid, usually soft, but always elastically deformable under load. After stress, elastomers return to their initial shape.
When heated, elastomers do not become plastic (and are not deformable), and will not melt. At high temperatures decomposition takes place and the material is destroyed. Elastomers are non-meltable, non- weldable, and insoluble, but they are resolvable.
The elasticity of an elastomer material is defined by the degree of cross-linking. The linking process is called vulcanization or curing. Vulcanized elastomers are also called “rubber”.
EPDM rubber (ethylene propylene diene monomer (M-class) rubber), a type of synthetic rubber, is an elastomer with a wide range of applications. The E refers to ethylene, P to propylene, D to diene, and M to its classification in ASTM standard D-1418.
EPDM rubber is used in seals, glass run channels, radiators, garden and appliance hoses, tubing, washers, belts, electrical insulation, vibrators, and speaker cone surrounds. It is also used as a medium for water resistance in electrical cable-jointing, roofing membranes, geomembranes, rubber mechanical goods, plastic impact modification, thermoplastics, vulcanizates, and many other applications.
The main properties of EPDM are its outstanding resistance to heat, ozone and weather. Its resistance to polar substances and steam is also good, and it has excellent electrical insulating properties.