EPDM (ethylene propylene diene) is a copolymer of ethylene, propylene and a small amount of non conjugated diene Monomer) said that because its main chain is composed of chemically stable saturated hydrocarbons and only contains unsaturated double bonds in the side chain, it has excellent ozone resistance, heat resistance, weather resistance and other anti-aging properties, and can be widely used in automobile parts, building waterproof materials, wire and cable sheaths, heat-resistant rubber tubes, tapes, automobile seals and other fields.

1. Low density and high filling

The density of ethylene propylene rubber is a kind of lower rubber, its density is 0.87. In addition, a large amount of oil can be filled and fillers can be added, so as to reduce the cost of rubber products and make up for the high price of raw ethylene propylene rubber. Moreover, for ethylene propylene rubber with high Mooney value, the physical and mechanical energy after high filling is not greatly reduced.

2. Aging resistance

EPDM has excellent weather resistance, ozone resistance, heat resistance, acid and alkali resistance, water vapor resistance, color stability, electrical properties, oil filling and room temperature fluidity. Ethylene propylene rubber products can be used for a long time at 120 ℃, and can be used briefly or intermittently at 150-200 ℃. The use temperature can be increased by adding suitable antioxidant. EPDM crosslinked with peroxide can be used under harsh conditions. When the concentration of ozone was 50 PPHM and the tensile strength was 30%, the EPDM rubber could not crack for more than 150 hours.

3. Corrosion resistance

Due to the lack of polarity and low unsaturation, ethylene propylene rubber has good resistance to various polar chemicals such as alcohols, acids, bases, oxidants, refrigerants, detergents, animal and vegetable oils, ketones and fats; but it is less stable in aliphatic and aromatic solvents (such as gasoline, benzene, etc.) and mineral oils.

4. Steam resistance

Ethylene propylene rubber has excellent water vapor resistance and is estimated to be superior to its heat resistance. In 230 ℃ superheated steam, there is no change in appearance after nearly 100 h. However, under the same conditions, the appearance of fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, nitrile rubber and natural rubber had obvious deterioration after a short time under the same conditions.

5. Resistance to superheated water

The resistance of ethylene propylene rubber to hot water is also good, but it is closely related to all curing systems. The mechanical properties of ethylene propylene rubber (EPDM) vulcanized with dimethomorphine disulfide and TMTD as vulcanization system changed little after soaking in superheated water at 125 ℃ for 15 months, and the volume expansion rate was only 0.3%.

6. Electrical properties

EPDM has excellent electrical insulation and corona resistance, and its electrical properties are better than or close to those of styrene butadiene rubber, chlorosulfonated polyethylene, polyethylene and cross-linked polyethylene.

7. Elasticity

Due to the fact that there are no polar substituents in the molecular structure of ethylene propylene rubber (EPR), the molecular chain can maintain flexibility in a wide range, which is second only to natural rubber and cis-1,4-polybutadiene rubber, and can still maintain at low temperature.

8. Adhesion

Due to the lack of molecular structure of EPDM, it is easy to spray.