ETHYLENE-PROPYLENE RUBBER(EPM)&(EPDM) (VULCNIZATE PROPRTIES (EPM and…
2 types: EPM (ethylene-propylene monomer) & EPDM (ethylene-propylene diene monomer)
three basic dienes used as the third monomer:
a. 1,4 hexadiene (1,4 HD)
b. Dicyclopentadiene (DCPD) and
c. 5-ethylidiene norbonene (ENB)
A copolymer of polyethylene and polypropylene produced by solution and suspension polymerization
being completely saturate, require organic peroxide or radiation for vulcanization.
EPDM terpolymer can be vulcanized with peroxide, radiation or sulphur
contain carbon black or light fillers or both, zinc oxide, antioxidants, processing aids, petroleum based plasticizers and curing ingredients.
higher ethylene content can be more easily processed and more highly loaded with fillers and oils, but the vulcanizates will be exhibit inferior low temperature properties and high compression set.
EPDM grades containing ENB as a dyne component have greater reactivity toward sulphur vulcanization and the reactivity increases with increasing the ENB level.
have fair tensile strength over a wide hardness range
Excellent resistance to weathering,ozone,oxygen
Excellent electrical insulation
Peroxide cured compounds exhibit excellent heat aging
Sulphur cured EPDM compounds have high compression set and are less resistant to high temperature
EPM and EPDM vulcanizates are resistant to:
• Nonpetroleum based automotive brake fluids
• Aryl and alkyl-aryl phosphate esters
• Hot water and steam
• Polyalkylene-glycol based fluids.
• Alcohols, ketones and low molecular weight esters
• Silicone oils and greases.
EPM and EPDM vulcanizates are not resistant to:
• Mineral oil based fluids and greases
• Hydrocarbon fuels
• Synthetic hydrocarbon lubricants
Wire and cable