Characteristics and application of EPDM rubber materials

EPDM, abbreviated as EPDM, is a widely used synthetic rubber. It has excellent resistance to thermal oxygen, photooxygen and ozone aging properties, good acid and alkali resistance and electrical insulation. At present, it is widely used in automobile parts, waterproof materials for construction, wire and cable protective covers, heat-resistant hose, transport belt and automobile seals and other products.

For such a wide range of EPDM materials, we have a deep understanding of it from the following aspects:

1 Overview

Epdm rubber, as the name suggests, is made of ethylene, propylene and the third monomer polymerization, of which ethylene and propylene usually account for more than 90% of the whole.

The double bond structure of ethylene and propylene monomer opens into a single bond during the polymerization process, which makes EPDM molecule highly saturated, resistant to thermal oxygen aging, and highly resistant to light, that is, ozone.

The temperature resistance of traditional EPDM materials exceeds that of unsaturated rubbers such as natural rubber, styrene butadiene rubber and nitrile butadiene rubber. Specific formulations of EPDM materials can be used at 150℃ for a short period of time and at 125℃ for a long period of time.

In addition to high temperature resistance, EPDM low temperature resistance is also very good, soft molecular chain structure, it will not be brittle at -55℃.

The relatively large short-plate performance of EPDM material is that it is not resistant to mineral oil, which also depends on its molecular structure: ethylene and propylene carbon chain molecules, the structure is very similar to mineral oil, due to the similar solubility, EPDM material will swell in mineral oil and lose function.

The random arrangement of ethylene and propylene makes the mechanical properties of EPDM material much different from crystalline rubber such as natural rubber, so EPDM usually needs to use reinforcing agents such as carbon black to improve its strength. Under the reinforcement of carbon black, its mechanical properties can be advanced with natural rubber. Of course, this is also the reason why EPDM materials are mostly black.

2 Special application of our EPDM

Knowing the advantages and disadvantages of EPDM, we can use it to maximize the function of the material. However, in some specific occasions, or in the blank area of various material application conditions, we still need to continue to modify EPDM materials to achieve our use expectations. To this end, we have developed or are developing some special EPMD materials:

2.1 Self-lubricating EPDM material

The friction coefficient of rubber materials is generally large, which brings obstacles to the installation of some rubber products with interference fit. To this end, our company developed a self-lubricating EPDM material, which will slowly seep grease after the product is formed, reduce the friction coefficient of the surface of rubber products, and facilitate installation. The amount of oil seepage can be adjusted according to demand, and the oil seepage has no effect on the performance of rubber products.

2.2 EPDM material resistant to 150℃

Specific formulations of EPDM materials, short-term temperature resistance can reach 150℃, but this temperature for conventional EPDM materials is the limit temperature, continuous use at this temperature, the material performance will have a greater loss. Our current high temperature EPDM material, 150℃ x 3 days performance loss < 10%, for some products that need to be used continuously at 150℃, its safety is higher.

3 Development direction of EPDM materials

At present, with the increasing application requirements, EPDM materials are also developing towards higher performance and wider applications.

3.1 Higher operating temperature

At present, our company is developing a new type of EPDM material, which can be increased to 175℃ for short-term use. The new EPDM material uses a special third monomer as the cross-linking point, and the molecular chain structure of EPDM after vulcanization is more regular, and the temperature resistance is better. The performance loss at 175℃ is similar to that of conventional silica gel, but the mechanical properties are obviously better than that of silica gel.

3.2 Lower operating temperature

Our company is developing another kind of information EPDM material, its molecular species introduced butene, so that its molecular steric resistance is reduced, low temperature resistance level is expected to continue to reduce 10℃ to 15℃ on the original basis, can effectively solve the use of some cold areas.

3.3 Environmental protection and flame retardant

Conventional EPDM material flame retardant effect is poor, if there are V0 grade flame retardant requirements, or add a large number of inorganic flame retardants, sacrifice performance to meet the requirements; Or it is necessary to add flame retardants containing decabromodiphenyl ethane and antimony oxide, which sacrifices environmental performance to a certain extent. In this regard, our company is developing environmentally friendly flame retardant EPDM material, the current test of its flame retardant grade can reach V0 requirements, and due to high flame retardant efficiency, small amount of flame retardants added, no significant decline in material performance, in the rapid development of new energy vehicles at present, can be applied to more corresponding conditions.

3.4 Oil Resistance

The oil resistance of traditional EPDM materials is very poor, which also makes some parts do not contact oil in normal working conditions, but they may contact some parts in maintenance or abnormal situations. Our company is currently developing a new EPDM material, can be applied to such conditions, in the case of surface coating, dripping mineral oil, EPDM material has no obvious appearance changes, and in the long-term high temperature mineral oil soaking, the volume change can remain less than 80%.

The research of EPDM rubber is a microcosm of our company's technological development. All along, we have never stopped the exploration of technology, we will "create a better future with the wisdom of employees, create a happy life for employees with the good of the company" as a mission, give full play to the wisdom of employees. We continue to innovate, because "to become a model of the industry and a first-class supplier in the global supply chain, to make due contributions to China's polymer products industry" is our vision. Our original innovation can provide you with a more convenient solution.