A overview of the differences between EPDM and silicone rubber!
Both silicone and EPDM are often used rubbers in industrial applications, with silicone acting as a general-purpose rubber and EPDM as a more specialised rubber. Both are occasionally confused for one another. What distinguishes EPDM from silicone, and when should you choose one over the other?
Ethylene Propylene Diene Monomer is referred to as EPDM. It is a synthetic rubber that is widely used in the automotive and construction sectors. Polydimethylsiloxane, also known as silicone, is an inorganic polymer derived from quartz sand. Applications for it include everything from food and drink to aerospace and the automotive industry.
What is EPDM ?
The resistance of EPDM (Ethylene Propylene Diene Monomer) rubber to water, heat, cold, weather, ozone, UV radiation, steam, electricity, and abrasion makes it a preferred option for outdoor and severe environment applications. Polymethylene's single bond, chemically saturated backbone makes up EPDM. Its inability to withstand substances like oil, grease, hydrocarbon fuel, strong acid, and halogenated solvent is where this material falls short. Roofing, plumbing, HVAC, and automotive sectors all frequently use EPDM.
What is silicone ?
The best-known properties of silicone, commonly referred to as polysiloxane, are its flexibility and temperature tolerance. Yet it's also nonstick, gas permeable, flame-resistant, hypoallergenic, and chemically inert. The inorganic silicon-oxygen backbone of silicone rubber is bonded to organic molecules, making it an elastomer, an elastic polymer. Silicone rubber is produced by removing silicon from silica, processing the resultant material through hydrocarbons, and then combining it with other chemicals.
Alkali, acid, trichloroethylene, steam, aromatic hydrocarbons, or hydrocarbon fuel are not resistant to silicone. The substance is typically used in HVAC, electronics, industrial, aerospace, construction, automotive, and medical applications.
What's the difference between EPDM and Silicone?
Both silicone and EPDM are synthetic rubbers, but the main distinction between the two is how broadly they may be used. While EPDM is better suited for more specialised usage, silicone is better for more general ones. Both rubbers have strong bonds with metal and are resistant to electricity, the elements, ozone, and UV light.
Silicone is more flexible in its applications, but it’s also more expensive. The material is able to function under much higher temperatures than EPDM, with a range of about 150 degrees F more at 446 F (230 C), while still being able to function at the same minimum temperatures of around -58 degrees F (-50 degrees C). Silicone is also commonly used for food safe uses, while EPDM is unsafe for those applications. Additionally, automotive fluids that would break EPDM down are not an issue for silicone, and it has a better compression set and longer lifespan.
Contrarily, EPDM is a more specialised rubber with higher performance and lower cost in particular applications. Although both rubbers are regarded as waterproof, EPDM doesn't change when silicone is exposed to water. It can function in steam at temperatures of up to 392 degrees Fahrenheit (200 degrees Celsius) without air, whereas silicone can only do so at 249 degrees Fahrenheit (121 C). Along with having approximately three times the tensile strength of silicone rubber at 14 MPa, EPDM is also more resistant to weather and abrasion than silicone rubber.
Conclusion
Both EPDM and silicone have their merits and drawbacks, depending on the application they’re used for.
