EPDM Rubber Encyclopedia

Can EPDM recycled rubber produce cold resistant rubber products?

Create Date:2023-03-15 14:35:53Click volume:2100
Can EPDM recycled rubber produce cold resistant rubber products?

Many rubber products on the market need to work under low temperature conditions, such as automotive brake seals working in cold areas. It is required that the rubber material will not undergo brittle fracture under low temperature conditions and can maintain its original elasticity and flexibility, and the permanent deformation of low temperature compression is good; Ethylene-propylene rubber is a non-polar rubber with good flexibility. Its glass transition temperature is low, and its low temperature performance is good. The minimum service temperature can reach below - 50 ℃. As a low-cost raw material for EPDM, can EPDM recycled rubber be used in the production of cold-resistant rubber products? What should we pay attention to?

1. Raw rubber selection skills for cold-resistant rubber products produced by EPDM recycled rubber

Cold resistant rubber gasket

EPDM recycled rubber is mostly used with EPDM raw rubber to produce cold-resistant rubber products. When the ethylene content in EPDM is 40% - 60%, it has the lowest glass transition temperature, and the low temperature performance of the obtained rubber compound is the best; Wide ethylene composition distribution will increase the length of ethylene chain segment and crystal composition, resulting in poor low-temperature performance of rubber compound. Therefore, when EPDM recycled rubber is used to produce cold-resistant molded products, it is recommended to use it in combination with EPDM with excellent low-temperature compression set performance with ethylene content less than 50% and very narrow composition distribution.

2. Design of reinforcement system for cold-resistant rubber products produced by EPDM recycled rubber

When EPDM/EPDM reclaimed rubber is used to produce cold resistant rubber products, it is recommended to use carbon black with low or medium reinforcement as far as possible to give the rubber material good elastic and dynamic properties. spray carbon black is commonly used. In actual production, carbon black with good reinforcing performance has strong interaction with macromolecules, which will limit the activity of macromolecules and may have adverse effects on the cold resistance of rubber compound.

Low temperature resistant rubber pipe

3. Design of softening system for cold-resistant rubber products produced by EPDM recycled rubber

Softener has lubricating effect on macromolecules in rubber, can improve the mobility of macromolecules, and can improve the low-temperature performance of rubber compound. When using EPDM/EPDM recycled rubber 2SLYY315 to produce cold-resistant rubber products, the use of softeners with low freezing point, strong plasticizing effect and good compatibility has a significant effect on improving the cold-resistance of the rubber compound, and the greater the dosage, the more obvious the effect; It is recommended to use ester plasticizers (such as DOS, DBS, DOA, DBP, DOP, etc.), naphthenic oil or paraffin oil with medium or low viscosity.

4. Design of curing system for cold-resistant rubber products produced by EPDM recycled rubber

EPDM reclaimed rubber

When EPDM/EPDM recycled rubber is used to produce cold-resistant rubber products, the type and density of cross-linking bond also have an impact on the low-temperature performance of the rubber compound. In actual production, the low-temperature performance of EPDM peroxide vulcanizate is better than that of sulfur vulcanizate. The good elasticity of peroxide vulcanizate makes macromolecules have a faster response to external forces. Considering the degree of crosslinking, moderate crosslinking reduces the regularity of molecular chain and improves the low-temperature performance; However, if the degree of crosslinking is too deep, the modulus will increase, and the molecular activity will be limited, so the low-temperature performance of the rubber compound will also be adversely affected.

The use of EPDM recycled rubber reduces the production cost of cold-resistant rubber products. What other factors will affect the cold-resistance of EPDM vulcanizates? The following editor will continue to discuss relevant issues with you.

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