Material detail – EPDM
EPDM (ethylene propylene diene monomer)synthetic rubber is an elastomer with a variety of applications and manufacturing methods.
A versatile material with excellent waterproofing, electrical insulation and noise reducing qualities, with good resistance to ketones, ordinary diluted acids, and alkalies. EPDM rubber is commonly used to manufacture panel seals, cable joints, insulation membranes, O-rings and washers.
EPDM rubbers continue to be one of the most widely used and fastest growing synthetic rubbers having both specialty and general-purpose applications. Ethylene-propylene rubbers are valuable for their excellent resistance to heat, oxidation, ozone and weather aging due to their stable, saturated polymer backbone structure. Properly pigmented black and non-black compounds are color stable. As non-polar elastomers, they have good electrical resistivity, as well as resistance to polar solvents, such as water, acids, alkalies, phosphate esters and many ketones and alcohols. Amorphous or low crystalline grades have excellent low temperature flexibility with glass transition points of about minus 60°C. Heat aging resistance up to 130°C can be obtained with properly selected sulfur acceleration systems and heat resistance at 160°C can be obtained with peroxide cured compounds. Compression set resistance is good, particularly at high temperatures, if sulfur donor or peroxide cure systems are used. These polymers respond well to high filler and plasticizer loading, providing economical compounds. They can develop high tensile and tear properties, excellent abrasion resistance, as well as improved oil swell resistance and flame retardance¹.
EPDM exhibits satisfactory compatibility with fireproof hydraulic fluids, ketones, hot and cold water, and alkalis but drawbacks include it’s unsatisfactory compatibility with most oils, petroleum, kerosene, aromatic and aliphatic hydrocarbons, halogenated solvents, and concentrated acids.
Properties of EPDM²
|Hardness, Shore A||40-90|
|Tensile Failure Stress, ultimate||25 MPa|
|Elongation after Fracture in %||≥ 300%|
|Density||Can be compounded from 0.90 to >2.00 g/cm3|
|Coefficient of Thermal Expansion, Linear||160 µm/m·K|
|Maximum Service Temperature||150 °C|
|Minimum Service Temperature||−50 °C|
|Glass Transition Temperature||−54 °C|