Description of the performance of the seat material EPDM

Ethylene propylene rubber EPDM(E)
EPDM rubber is a rubber obtained by copolymerization of ethylene and propylene, and a third monomer (ENB) is introduced. EPDM rubber is basically a saturated high polymer with excellent aging resistance, good weather resistance, excellent electrical insulation performance, good chemical corrosion resistance and good impact elasticity. The main disadvantage of ethylene-propylene rubber is that the vulcanization rate is slow; it is difficult to use with other unsaturated rubbers, and the self-adhesiveness and mutual viscosity are very poor, so the processing performance is not good.
According to the performance characteristics of ethylene-propylene rubber, it is mainly used in several fields requiring anti-aging, water resistance, corrosion resistance and electrical insulation, such as light-colored sidewalls for tires, heat-resistant conveyor belts, cables, wires, anti-corrosion linings, and gaskets. , building waterproof sheet, door and window seals, household appliances accessories, plastic modification, etc. The nature and use of ethylene propylene rubber.
Ethylene-propylene rubber is synthesized from ethylene and propylene as main raw materials, and its aging resistance, electrical insulation properties and ozone resistance are outstanding. Ethylene-propylene rubber can be filled with oil and filled with carbon black. The price of the product is low. The chemical stability of ethylene-propylene rubber is good, and the wear resistance, elasticity, oil resistance and styrene-butadiene rubber are close. Ethylene-propylene rubber is widely used as a tire side, rubber strip and inner tube, as well as automotive parts. It can also be used as wire and cable sheathing and high-voltage, ultra-high-voltage insulation materials. It can also manufacture light-colored products such as shoes and hygiene products. Performance and improvement of ethylene propylene rubber:

1. Low density and high filling
The density of ethylene propylene rubber is a lower rubber with a density of 0.87. In addition, the oil can be filled in a large amount and the filler is added, thereby reducing the cost of the rubber product, making up for the disadvantage of the high price of the rubber of the ethylene propylene rubber, and for the high Mooney value of the ethylene propylene rubber, the physical mechanical energy can be reduced after the high filling. Not big.
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 temporarily or intermittently at 150-200 ° C. Adding a suitable anti-aging product can increase its use temperature. The peroxide-crosslinked EPDM rubber can be used under severe conditions. EPDM rubber can be cracked for more than 150h under the condition of 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 alcohols, acids, alkalis, oxidants, refrigerants, detergents, animal and vegetable oils, ketones and fats. However, it is less stable in aliphatic and aromatic solvents (such as gasoline, benzene, etc.) and mineral oil. The performance also decreases under the long-term effect of concentrated acid. In ISO/TO 7620, data on the effects of corrosive gaseous and liquid chemicals on various rubber properties are compiled, and 1-4 grades are indicated for their degree of action. Corrosive chemicals have an effect 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 serious
4, water vapor resistance
Ethylene-propylene rubber has excellent water vapor resistance and is superior to its heat resistance. In the superheated steam at 230 ° C, there was no change in appearance after nearly 100 h. Fluorine rubber, silicone rubber, fluorosilicone rubber, butyl rubber, nitrile rubber, and natural rubber experienced significant deterioration in appearance over a short period of time under the same conditions.
5, resistance to hot water performance
Ethylene-propylene rubber is also resistant to superheated water, but is closely related to all vulcanization systems. The ethylene-propylene rubber with dimorpholine disulfide and TMTD as the vulcanization system has a very small change in mechanical properties after soaking in 125 ° C superheated water for 15 months, and the volume expansion ratio is only 0.3%.
   6, electrical performance
Ethylene-propylene rubber has excellent electrical insulation properties and corona resistance, and its electrical properties are superior to or close to styrene-butadiene rubber, chlorosulfonated polyethylene, polyethylene and cross-linked polyethylene.
   7, flexibility
Since there is no polar substituent in the molecular structure of ethylene-propylene rubber, the molecular cohesive energy is low, and the molecular chain can maintain flexibility in a wide range, which is second only to natural commercial and butadiene rubber, and can be maintained at low temperatures.
8, adhesion
Ethylene-propylene rubber lacks active groups due to its molecular structure, low cohesive energy, and the rubber is easy to bloom, and its self-adhesiveness and mutual viscosity are poor.
Second, ethylene-propylene rubber modified varieties.
Since the successful development of EPDM and EPDM rubber in the late 1950s and early 1960s, a variety of modified ethylene propylene rubber and thermoplastic ethylene propylene rubber (such as EPDM/PE) have appeared in the world. The wide application of ethylene propylene rubber provides a wide variety of varieties and grades. The modified ethylene-propylene rubber mainly uses brominated, chlorinated, sulfonated, maleic anhydride, maleic anhydride, silicone modified, and nylon modified ethylene-propylene rubber. Ethylene-propylene rubber is also grafted with acrylonitrile, acrylate, and the like. Over the years, many polymer materials with good comprehensive properties have been obtained by means of blending, copolymerization, filling, grafting, reinforcement and molecular compounding. The modification of ethylene propylene rubber has also greatly improved the performance, which has expanded the application range of ethylene propylene rubber.
Ethylene propylene bromide rubber is treated with a brominating product on an open mill. After bromination, ethylene propylene rubber can improve its vulcanization speed and adhesive performance, but the mechanical strength is reduced. Therefore, ethylene bromide rubber is only suitable for the interposer of ethylene propylene rubber and other rubber.
Ethylene propylene chloride rubber is made by passing chlorine gas through a solution of ethylene propylene diene rubber. After chlorination of ethylene propylene rubber, the vulcanization speed and compatibility with unsaturated sputum, fire resistance, oil resistance and adhesion properties are also improved.
The sulfonated ethylene propylene rubber is prepared by dissolving ethylene propylene diene monomer in a solvent and treating it with a sulfonating product rubber neutralizing product. Sulfonated ethylene-propylene rubber will be widely used in adhesives, coated fabrics, building waterproof lean meat, anti-corrosion lining, etc. due to its thermoplastic elastomer and good adhesion properties.
The acrylonitrile-grafted ethylene-propylene rubber was grafted with ethylene propylene rubber at 80 ° C using toluene as a solvent and benzyl chloride as an initiator. The acrylonitrile-modified ethylene-propylene rubber not only retains the corrosion resistance of ethylene-propylene rubber, but also obtains the oil resistance equivalent to nitrile-26, and has good physical and mechanical properties and processing properties.
Thermoplastic ethylene propylene rubber (EPDM/PP) is a blend of polypropylene and EPDM rubber. At the same time, the ethylene propylene rubber reaches the product of the expected degree of crosslinking. Not only does it retain the inherent properties of ethylene propylene rubber in terms of performance, but it also has significant process properties for injection, extrusion, blow molding and calendering of thermoplastics.
In addition, the modified ethylene propylene rubber is also chlorosulfonated ethylene propylene phthalate, acrylate grafted ethylene propylene rubber and the like.