Ethylene propylene diene monomer rubber O-ring (EPM/EPDM)
（1） Molecular Structure
- (CH2-CH2) (CH2-CH) Ethylene Propylene Diene
CH3
- (CH2-CH2) (CH2-CH) M EPDM type
CH3
（2） Physical and chemical properties
The O-ring of EPDM rubber is made by copolymerizing ethylene and propylene, and the main chain does not contain double chains, so its heat resistance, weather resistance, and ozone resistance are all excellent. At an ozone concentration of 100 * 10-8 (pphm), no cracking occurs for 2430 hours, and the outdoor lifespan can reach over 25 years. In water vapor at 160 ℃, ethylene propylene rubber also exhibits superior performance compared to other general-purpose rubbers. It also has good resilience, insulation properties (volume resistance of about 10, breakdown voltage of 30-40kv/mm), and low temperature resistance (Tg=-60 ℃) EPDM (Ethylene Propylene Diene Monomer Rubber) is suitable for use in ethylene glycol based brake fluids, hot water and steam (up to 150 ℃), silicone oil and grease, animal and vegetable oils, most organic or inorganic acids, cleaning agents, soaps, and alkaline environments containing potassium at 150 ℃, most polar solvents (ketones, alcohols), phosphate hydraulic oils (Skydrol, Pydraul), and refrigerant R134a+PAG systems. It has good resistance to chlorine water and chlorine ammonia, and can also be used in acetic acid environments below 3% -5%. However, it is not suitable for mineral oils and fats, aromatic and olefin solvents. The disadvantages of EPDM rubber O-rings are slow vulcanization speed, inability to co vulcanize with diene rubber, poor self adhesion and mutual adhesion, and poor air tightness.
（3） Temperature range
-55 ℃~125 ℃, using organic peroxide sulfurization can reach up to 150 ℃
（4） Hardness range
Shore A 40 to 90 degrees
（5） Color
Black, brown, green, white, brownish red, yellow, blue, orange, gray, purple, colors can also be specified by the customer
（1） Application
Ethylene propylene rubber has a wide range of applications in the automotive industry. It can be used to make automotive diaphragms, cups, dust covers, brake components, radiators and water tanks, engine connecting hoses, shock absorbers, as well as door and window seals, lights, and luggage compartment seals. Ethylene propylene rubber can be used as a waterproof material when combined with asphalt in the construction industry. It can be used to make shock-absorbing products in the bridge industry, plastic steel door and window seals for high-rise buildings, and rubber floor tiles for indoor use. Ethylene propylene rubber can be used as an insulation material for transformers and can also be made into other high, medium, and low voltage insulation products. Ethylene propylene rubber can be used to make various chemical corrosion-resistant products, such as acid, alkali, ammonia, chloride resistant lining, various rubber hoses, heat-resistant conveyor belts, transmission belts, gaskets, and seals. And magnetic sealing strips in household appliances, cooling and heating fan parts, washing machine seals, vacuum cleaners, cloth clip rubber boats, etc.
