Relative to rubbers with unsaturated backbones (
natural rubber,
SBR,
neoprene), rubbers with saturated polymer backbones, such as EPDM, exhibit superior resistance to heat, light, and ozone exposure. For this reason they are useful in external harsh environments. EPDM in particular exhibits outstanding resistance to
heat,
ozone,
steam, and
weather. As such, EPDM can be formulated to be resistant to temperatures as high as 150 °C, and, properly formulated, can be used outdoors for many years or decades without degradation. EPDM has good low-temperature properties, with elastic properties to temperatures as low as −40 °C depending on the grade and the formulation. on the back, used for
waterproofing roofs EPDM is stable towards fireproof
hydraulic fluids, ketones, hot and cold water, and alkalis. As a durable
elastomer, EPDM is conformable, impermeable, and a good electrical insulator. Solid EPDM and expanded EPDM foam are often used for
sealing and
gasketing, as well as
membranes and
diaphragms. EPDM is often used when a component must prevent
fluid flow while remaining flexible. It can also be used to provide
cushioning or
elasticity. While EPDM has decent
tensile strength, its flexibility makes it inappropriate for rigid parts such as
gears,
shafts, and structural beams. It is used to create weatherstripping, seals on doors for
refrigerators and
freezers (where it also acts as an
insulator), face masks for industrial respirators,
glass run channels,
radiators, garden and appliance
hose (where it is used as a hose material as well as for gaskets),
tubing,
washers,
O-rings,
electrical insulation, and
geomembranes. A common use is in
vehicles, where EPDM is used for door seals, window seals, trunk seals, and sometimes hood seals. Other uses in vehicles include
wiper blades, cooling system circuit hoses; water pumps, thermostats, EGR valves, EGR coolers, heaters, oil coolers, radiators, and degas bottles are connected with EPDM hoses. EPDM is also used as charge air tubing on
turbocharged engines to connect the cold side of the charge air cooler (
intercooler) to the
intake manifold. When the refrigerant oil is synthetic, such as in the case of
R-134a and PAG oil, EPDM orings can be used in air conditioning systems. EPDM seals can be a source of squeaking noise due to the movement of the seal against the opposing surface (and its attendant friction). The noise can be alleviated using specialty coatings that are applied at the time of manufacture of the seal. Such coatings can also improve the chemical resistance of EPDM rubber. Some vehicle manufacturers also recommend a light application of
silicone dielectric grease to weatherstrip to reduce noise. This synthetic rubber membrane has also been used for pond liners and
flat roofs because of its durability and low maintenance costs. As a
roofing membrane it does not pollute the run-off rainwater (which is of vital importance for
rainwater harvesting). It is used for
belts,
electrical insulation,
vibrators,
solar panel heat collectors, and speaker cone surrounds. It is also used as a functional additive to modify and enhance the impact characteristics of
thermoset plastics,
thermoplastics, and many other materials. EPDM is also used for components that provide
elasticity; for example, it is used for
bungee cords, elastic tie-downs, straps, and hangers that attach exhaust systems to the underfloor of vehicles (since a rigid connection would transfer vibration, noise, and heat to the body). It is also used for cushioned edge guards and bumpers on appliances, equipment, and machinery. Colored EPDM granules are mixed with polyurethane binders and troweled or sprayed onto concrete, asphalt, screenings, interlocking brick, wood, etc., to create a non-slip, soft, porous safety surface for wet-deck areas such as pool decks. It is used as safety surfacing under playground play equipment (designed to help lessen fall injury). ==Further reading==