EPDM rubber

Rubber

Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...

(ethylene propylene diene monomer (M-class) rubber), a type of synthetic rubber

Synthetic rubber

Synthetic rubber is is any type of artificial elastomer, invariably a polymer. An elastomer is a material with the mechanical property that it can undergo much more elastic deformation under stress than most materials and still return to its previous size without permanent deformation...

, is an elastomer

Elastomer

An elastomer is a polymer with the property of viscoelasticity , generally having notably low Young's modulus and high yield strain compared with other materials. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, although the latter is preferred...

 which is characterized by a wide range of applications. The E refers to ethylene

Ethylene

Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...

, P to propylene

Propylene

Propene, also known as propylene or methylethylene, is an unsaturated organic compound having the chemical formula C3H6. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons, and it is also second in natural abundance.-Properties:At room temperature and...

, D to diene

Diene

In organic chemistry a diene or diolefin is a hydrocarbon that contains two carbon double bonds.Conjugated dienes are functional groups, with a general formula of CnH2n-2. Dienes and alkynes are functional isomers...

 and M refers to its classification in ASTM standard D-1418. The M class includes rubbers having a saturated chain of the polymethylene type. Dienes currently used in the manufacture of EPDM rubbers are dicyclopentadiene (DCPD), ethylidene norbornene (ENB), and vinyl norbornene (VNB).
The ethylene content is around 45% to 75%. The higher the ethylene content the higher the loading possibilities of the polymer, better mixing and extrusion. Peroxide curing these polymers give a higher crosslink density compared with their amorphous

Amorphous solid

In condensed matter physics, an amorphous or non-crystalline solid is a solid that lacks the long-range order characteristic of a crystal....

 counterpart. The amorphous polymer are also excellent in processing. This is very much influenced by their molecular structure. The dienes, typically comprising from 2.5% up to 12% by weight of the composition, serve as crosslinks

Cross-link

Cross-links are bonds that link one polymer chain to another. They can be covalent bonds or ionic bonds. "Polymer chains" can refer to synthetic polymers or natural polymers . When the term "cross-linking" is used in the synthetic polymer science field, it usually refers to the use of...

 when curing with sulphur and resin, with peroxide cures the diene (or third monomer) functions as a coagent, which provide resistance to unwanted tackiness, creep or flow during end use.

Usage

EPDM rubber is used in vibrators and seal

Seal (mechanical)

A mechanical seal is a device which helps join systems or mechanisms together by preventing leakage , containing pressure, or excluding contamination...

s; glass-run channel; radiator

Radiator

Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in automobiles, buildings, and electronics...

, garden and appliance hose

Hose (tubing)

A hose is a hollow tube designed to carry fluids from one location to another. Hoses are also sometimes called pipes , or more generally tubing...

; tubing

Tubing

Tubing may refer to:* Tubing , flexible hose or pipe * Tubing , the act of riding an inner tube* Structural tubing* Plumbing tube used in domestic water systems* Inserting a tube* Brass instrument tubing...

; washers

Washer (mechanical)

A washer is a thin plate with a hole that is normally used to distribute the load of a threaded fastener, such as a screw or nut. Other uses are as a spacer, spring , wear pad, preload indicating device, locking device, and to reduce vibration...

; belt

Belt (mechanical)

A belt is a loop of flexible material used to link two or more rotating shafts mechanically. Belts may be used as a source of motion, to transmit power efficiently, or to track relative movement. Belts are looped over pulleys. In a two pulley system, the belt can either drive the pulleys in the...

s; electrical insulation

Electrical insulation

thumb|250px|[[Coaxial Cable]] with dielectric insulator supporting a central coreThis article refers to electrical insulation. For insulation of heat, see Thermal insulation...

, 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, thermoplastic

Thermoplastic

Thermoplastic, also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently...

, vulcanizates

Vulcanization

Vulcanization or vulcanisation is a chemical process for converting rubber or related polymers into more durable materials via the addition of sulfur or other equivalent "curatives." These additives modify the polymer by forming crosslinks between individual polymer chains. Vulcanized material is...

, and many other applications.

EPDM exhibits satisfactory compatibility with fireproof hydraulic fluids, ketones, hot and cold water, and alkalis, and unsatisfactory compatibility with most oils, gasoline, kerosene, aromatic and aliphatic hydrocarbons, halogenated solvents, and concentrated acids.

The main properties of EPDM are its outstanding heat, ozone and weather resistance. The resistance to polar substances and steam are also good. It has excellent electrical insulating properties.

Typical properties of EPDM vulcanisates are given below. EPDM can be compounded to meet specific properties to a limit depending first on the EPDM polymers available, then the processing and curing method(s) employed. EPDMs are available in a range of molecular weights (indicated in terms of Mooney viscosity ML(1+4) at 125 °C), varying levels of ethylene, third monomer and oil content.

Mechanical properties
Hardness, Shore A	40–90
Tensile failure stress, ultimate	25 MPa
Density	Can be compounded from 0.90 to >2.00 g/cm3

Thermal properties
Coefficient of thermal expansion, linear	160 µm/m·K
Maximum service temperature	150 °C
Minimum service temperature	−50 °C
Glass temperature	−54 °C

Vehicles

EPDM rubber is commonly used in weatherseals on all vehicles. This includes door seals, window seals, trunk seals, and sometimes hood seals. Frequently these seals are the source of noise due to movement of the door versus the car body. This is due to friction between the EPDM rubber and the mating surface (car painted sheet metal or glass). This can be alleviated using specialty coatings that are applied at the time of manufacture of the weatherseal, not as an aftermarket application. Such coatings can also greatly increase the chemical resistance of EPDM rubber. Some vehicle manufacturers such as General Motors also recommend a light application of silicone dielectric grease to weatherstripping to reduce noise.

In general, EPDM is especially used in cooling system circuit hoses in an automobile. Water pump, thermostat, EGR valve, EGR cooler, heater, oil cooler, radiator and degas bottle is connected with hoses of which material is usually EPDM.

Additionally, EPDM can be used as charge air tubing on turbo charged engines. More specifically, it can be used to connect the cold side of the charge air cooler (intercooler) to the intake manifold.

Cold-room doors and refrigeration

EPDM provides good thermal resistance in insulation. It is used in cold-room doors for sealing purpose.

Safety equipment

EPDM is also commonly used as a material for the face seals of industrial respirators, most frequently chosen where the use of silicone must be avoided, typically in automotive paint spray environments.

Cable insulation

EPDM is also commonly used as a material for the outer casing on wires used on electrical appliances for outdoor installation, or exposed to UV light. E.g., for tubular motors for awnings, shutters, and roller blinds and also Venetian blind drives

Solar pool panels

Extruded EPDM is used to make a solar heat collector for swimming pool solar water heating systems.

Roofing

EPDM is used as a covering to waterproof roofs. It has the benefit that it does not pollute the run-off rainwater, which is of vital importance if the house owner wishes to use this water for personal sanitation/hygiene. Several houses equipped with rainwater harvesting

Rainwater harvesting

Rainwater harvesting is the accumulating and storing of rainwater for reuse before it reaches the aquifer. It has been used to provide drinking water, water for livestock, water for irrigation, as well as other typical uses. Rainwater collected from the roofs of houses and local institutions can...

 thus make use of this type of roofing.

Playground and pool deck surfacing

Granulated, colored EPDM granules are mixed with polyurethane binders and trowled 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 or playgrounds.

Pond liners

EPDM sheeting is used to line and waterproof man made ponds. Most back yard water gardens and koi pond

Koi pond

Koi ponds are ponds used for holding koi, usually as part of a landscape. Koi ponds can be designed specifically to promote health and growth of the Nishkigoi or Japanese Ornamental Carp....

s use an EPDM liner.