EPDM is an abbreviation for “Ethylene-Propylene-Methylene” and is a group of synthetic rubbers/elastomers. It is obtained by the co-polymerisation of ethylene (= ethylene), propylene (= propylene) and a die, which is an unsaturated hydrocarbon with two double bonds. EPDM is thus a ter-polymer, which is a polymer obtained from three monomers. After polymerisation, a thermoplastic polymer is obtained and one of the two double bonds of the diemonomer remains intact. This then allows the polymer to be vulcanised, forming standard sulphur bridges between the polymer molecules. Mixed with soot and other fillers, a rubber is then obtained, which has a number of attractive properties, such as:
- High elasticity up to 400% over a temperature range of -35 ° C to +120 ° C
- Good resistance to hot water, many bases, acids (including fatty acids) and salts (but not to earth & vegetable oil products) and ozone and UV rays. The ratio between the quantities of the different monomers used largely determines the properties of the EPDM polymer.
- Great material for sealing applications because of its excellent resistance to heat, water and steam, alkali, mild acid and oxygenated solvents, ozone and sunlight (UV).
- Also resistant to the effect of brake fluids and other hydraulic fluids based on phosphate esters. (Not resistant to hydraulic oil).
- Special EPDM compounds have good resistance to steam Not resistant to petrol, petroleum oil and grease and hydrocarbon environments
- EPDM sulfur vulcanized: cheap material for normal use, maximum temperature of + 120 ° C (+ 250 ° F).
- EPDM peroxide vulcanized: for hot water and/or low temperature steam, ketones, alcohols, engine coolants, organic and inorganic acids and alkalis. For maximum temperatures of + 150 ° C (+ 300 ° F).