1. Low density and high filling
Ethylene-propylene rubber is a rubber with a lower density, with a density of 0.87. In addition, it can be filled with a large amount of oil and EPDM.
Adding fillers can reduce the cost of rubber products and make up for the high price of ethylene propylene rubber raw rubber. For ethylene propylene rubber with high Mooney value, the physical and mechanical energy of high filling is not greatly reduced.
2. Aging resistance
Ethylene-propylene rubber has excellent weather resistance, ozone resistance, heat resistance, acid and alkali resistance, water vapor resistance, color stability, electrical properties, oil-filling properties and fluidity at room temperature. Ethylene-propylene rubber products can be used for a long time at 120°C, and can be used briefly or intermittently at 150-200°C. Adding suitable antioxidants can increase its use temperature. EPDM rubber cross-linked with peroxide can be used under harsh conditions. EPDM rubber can reach more than 150h without cracking under the conditions of ozone concentration 50pphm and 30% stretching.
3. Corrosion resistance
Because ethylene propylene rubber lacks polarity and low degree of unsaturation, it has good resistance to various polar chemicals such as alcohols, acids, alkalis, oxidants, refrigerants, detergents, animal and vegetable oils, ketones and greases. But it has poor stability in fatty and aromatic solvents (such as gasoline, benzene, etc.) and mineral oil. The performance will also decrease under the long-term action of concentrated acid. In ISO/TO 7620, nearly 400 kinds of corrosive gaseous and liquid chemicals have collected information on various rubber properties, and specified 1-4 levels to indicate their degree of action, and the impact of corrosive chemicals on rubber properties.
Grade Volume Swelling rate/% Hardness reduction value Impact on performance
1 <10 <10 slight or no
2 10-20 <20 smaller
3 30-60 <30 medium
4 >60 >30 severe
4. Water vapor resistance
Ethylene-propylene rubber has excellent water vapor resistance and is estimated to be better than its heat resistance. In 230℃ superheated steam, the appearance of EPDM remained unchanged after nearly 100h. However, under the same conditions, fluorine rubber, silicone rubber, fluorosilicone rubber, butyl rubber, nitrile rubber, and natural rubber experienced significant deterioration in appearance after a short period of time.
5. Superheated water resistance
Ethylene-propylene rubber also has better resistance to superheated water, but it is closely related to all vulcanization systems. Ethylene-propylene rubber with dimorpholine disulfide and TMTD as the vulcanization system, after being immersed in superheated water at 125°C for 15 months, the mechanical properties change very little, and the volume expansion rate is only 0.3%.
6. Electrical performance
Ethylene-propylene rubber has excellent electrical insulation properties 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. Flexibility
Because there are no polar substituents in the molecular structure of ethylene-propylene rubber, the cohesive energy of the molecule is low, and the molecular chain can maintain flexibility in a wide range, second only to natural negotiable and butadiene rubber, and can still be maintained at low temperatures.
8. Adhesion
Ethylene-propylene rubber lacks active groups due to its molecular structure and has low cohesive energy. In addition, the rubber is easy to bloom, and its self-adhesion and mutual adhesion are very poor.
Post time: Nov-17-2021