English full name: Ethylene - Propylene - Diene Monomer (hereinafter referred to as: EPDM)

EPDM rubber development history:
EPDM rubber is a terpolymer of ethylene, propylene and non-conjugation diolefin, EPDM rubber is basically a saturated high polymer, with very good aging resistance, good weather resistance, good electrical insulation, good chemical corrosion resistance, good impact elasticity. The main disadvantage of ethylene - propylene rubber is curing speed is slow; With other unsaturated rubber difficult to use, self - adhesive and mutual viscosity are very poor, so the processing performance is not good.
Commercial production began in 1963. World consumption is 800,000 tons a year. The main characteristics of EPDM are its superior oxidation resistance, ozone resistance and corrosion resistance. As EPDM belongs to the polyolefin family, it has excellent vulcanization characteristics. Of all rubbers, EPDM has the lowest specific gravity. It can absorb a large amount of filler and oil without affecting the properties. Therefore, cheap rubber compounds can be made.

EPDM rubber properties and application:
Mainly used in ageing resistance, water resistance, corrosion resistance, electrical insulation several areas, such as used in the light of the tire sidewall, heat resistant conveyor belt, EPDM rubber o-rings, EPDM gaskets, cable, wire, anti-corrosion lining, sealing washer, EPDM rubber, building waterproof sheet, doors and Windows, EPDM seal, household appliances accessories, plastic modification, etc.

EPDM rubber composition information:
EPDM rubber is synthesized with ethylene and propylene as the main raw materials. EPDM rubber can be filled with oil and carbon black, the product price is lower, EPDM rubber chemical stability, wear resistance, elasticity, oil resistance and styrene butadiene rubber close. Ethylene propylene rubber is widely used, can be used as tire side, rubber strip and inner tube as well as automobile parts, can also be used as wire, cable cover and high voltage, ultra high voltage insulation materials. Also can manufacture and shoes, sanitary products and other light - colored products. Properties and improvement of ethylene propylene rubber:

1. Low density and high filling property
EPDM rubber has a lower density of 0.87. In addition, it can be filled with a large amount of oil and filler, thus reducing the cost of rubber products, making up for the high price of EPDM rubber rubber, and for EPDM rubber with high menni value, the physical and mechanical energy decreases little after high filling.

2. Aging resistance
EPDM rubber has excellent weather resistance, ozone resistance, heat resistance, acid and alkali resistance, water vapor resistance, color stability, electrical properties, oil charging and normal temperature fluidity. Ethylene propylene rubber products at 120℃ can be used for a long time, in 150-200 ℃ can be used temporarily or intermittently. Adding suitable anti - aging agent can increase the use temperature. EPDM rubber crosslinked with peroxides can be used under harsh conditions. EPDM rubber can reach above 150h without cracking under ozone concentration of 50pphm and stretching of 30%.

3. Corrosion resistance
Due to the lack of polarity and low unsaturation of ethylene propylene rubber, it has good resistance to various polar chemicals such as alcohol, acid, alkali, oxidant, refrigerant, detergent, animal and vegetable oil, ketone and fat. However, the stability is poor in lipid and aromatic solvents (such as gasoline, benzene, etc.) and mineral oils. In the long - term action of concentrated acid performance will also decline. In ISO/TO 7620, data on the effects of nearly 400 corrosive gaseous and liquid chemicals on the properties of various rubbers are collected, and grades 1-4 are specified TO indicate the degree of effect. The effects of corrosive chemicals on the properties of rubbers are:

Effect of grade volume swelling rate /% hardness reduction on performance
1 <10 <10 slight or none
10 minus 20 is less than 20
30-60 <30 medium
4 >60 >30 serious

4. Water vapor resistance
EPDM rubber has excellent resistance to water vapor and is estimated to be superior to its heat resistance. In the superheated steam at 230℃, the appearance remained unchanged after nearly 100h. However, fluoro rubber, silicone rubber, fluoro silicone rubber, butyl rubber, nitrile butadiene rubber and natural rubber experienced obvious deterioration in a short time under the same conditions.

5. Resistance to hot water
EPDM rubber also has good over water resistance, but is closely related to all vulcanization systems. The ethylene-propyl rubber with dichmorpholine disulfide and TMTD as the curing system was immersed in 125℃ superheated water for 15 months, the mechanical properties changed little, and the volume expansion rate was only 0.3%.

6. Electrical performance
Ethylene-propylene rubber has excellent electrical insulation and corona resistance. Its electrical performance is better than or close to that of styrene-butadiene rubber, chlorosulfonated polyethylene, polyethylene and crosslinked polyethylene.

7, elastic
Due to the non-polar substituents in the molecular structure of EPDM rubber and the low molecular cohesion energy, the molecular chain can maintain the flexibility in a wide range, second only to natural rubber and butadiene rubber, and can maintain at low temperature.

8. Adhesion
Due to the lack of active groups in the molecular structure of EPDM rubber, low cohesion energy, plus the glue is easy to spray frost, self-viscosity and interviscosity is very poor.