Full definition
EPDM rubber, or ethylene-propylene-diene monomer terpolymer, is a synthetic rubber that is renowned for its versatility and durability in various industrial applications. Composed of ethylene, propylene, and a diene component, EPDM is characterized by its exceptional resistance to environmental factors such as ozone, ultraviolet (UV) radiation, and extreme weather conditions. This unique composition allows it to maintain its integrity and performance in challenging environments, making it an ideal material for applications exposed to hot water, steam, and polar chemicals. EPDM can withstand continuous service temperatures ranging from -50°C to +150°C, making it suitable for a wide range of applications, particularly in industries that require robust sealing solutions.
The material's physical properties are noteworthy; it has a hardness range of 30-90 Shore A, tensile strength between 7-21 MPa, and impressive elongation capabilities of 200-600%. These attributes contribute to EPDM's reputation for excellent electrical insulation as well as outstanding compression set resistance, which is crucial for maintaining a tight seal in various applications. EPDM is classified under ASTM D2000, with the standard grade designated as AA, while higher grades include BA, CA, and DA, reflecting their enhanced performance characteristics. The curing process for EPDM can utilize either sulfur or peroxide; sulfur curing requires a diene termonomer such as ethylidene norbornene (ENB) or dicyclopentadiene (DCPD) to achieve optimal properties.
Despite its numerous benefits, EPDM rubber does have limitations. It exhibits poor resistance to mineral oils, greases, and hydrocarbon solvents, which can lead to swelling and degradation upon exposure to these substances. This property must be considered when selecting EPDM for applications that might involve contact with such materials. Common applications of EPDM rubber include automotive door and window seals, roofing membranes (particularly single-ply systems), radiator and heater hoses, steam hoses, washing machine gaskets, electrical cable insulation, industrial rubber sheets, and expansion joints. With a global production nearing 1.5 million tonnes per year, leading manufacturers include Lanxess (Keltan), Dow (Nordel), Lion Copolymer, SK, and Mitsui, ensuring a robust supply chain for this critical material.