EPDM rubber is known for its properties as a polymer with excellent resistance to heat, weather and other demanding conditions.
These technical properties make EPDM an ideal elastomer for rubber articles designed for critical applications in automotive, aerospace, building and construction, tire and tubing, and consumer goods.
Like other rubbers, EPDM is traditionally made from petroleum-derived raw materials.
Specifically, the conventional EPDM polymer is made from petroleum-derived ethylene, propylene and diene monomers (hence the acronym EPDM).
However, as end-use EPDM markets try to reduce their CO2 footprints, especially in the automotive and transportation sectors, companies are aiming to integrate renewable ingredients into manufacturing processes and increase the sustainability of their final products.
But when manufacturers seek renewable materials as drop-in replacements for technical products, they usually don’t expect to see viable options for high performance rubber applications.
And, until the arrival of Arlanxeo’s Keltan® eco EPDM, these options were basically non-existent.
The First Commercialized Biobased EPDM
Keltan® eco EPDM is produced by Arlanxeo, a joint venture between Lanxess and Saudi Aramco. It was developed at pilot scale in 2011, and became the first commercially available biobased EPDM in 2013.
The Keltan® eco line includes six (6) grades of eco EPDM. Ranging from 50 – 70% in biobased content, these products have already been used to enhance sustainability profiles in several key application areas where performance expectations are high.
What Makes it ‘Eco’?
The ‘eco’ in this equation is attributed to the ethylene component of the EPDM.
Specifically, Arlanxeo is using bio-ethylene produced by Braskem.
The ethanol in eco EPDM is derived from sugar cane.
Braskem produces its biobased ethylene from renewable sugar cane at its Triunfo, Brazil production facility. The bio-ethylene is then used in the production of “I’m green™” polyethylene resins.
Arlanxeo is taking this same sugar cane derived raw material and applying it as the single biobased component in their eco EPDM series.
Arlanxeo notes that the only difference between their eco EPDM and conventional petroleum-based EPDM is the renewable origins of its ethanol.
Therefore, all other technical performance properties – including thermal and oxidative resistance, processing and handling properties, and health and safety aspects – remain intact.
Because eco EPDM is offered as an equivalent in terms of performance, it can be found in the same critical rubber applications as conventional EPDM.
For example, traditional EPDM has better heat resistance than other elastomers, such as natural rubber, SBR and butadiene rubber.
Because of these advanced characteristics, EPDM is used to make seals in critical under-the-hood automotive applications, such as seals for coolants, steam, synthetic hydraulic fluids, brake fluids and more.
The EPDM used in these seals is designed to withstand temperatures up to 150°C.
EPDM is ideal for high heat automotive seal applications.
EPDM is also used in household appliance applications, geothermal installations and aerospace components. And it is increasingly used as a polymeric additive in lubricant formulations.
While the technical properties may be equal, the sustainability advantage of using eco EPDM appears to be significant.
As mentioned, heavy manufacturing sectors are looking to reduce their overall carbon footprint.
For large automotive companies, promoting an overall life cycle approach to production processes and supply chain management, this is a key part of their global sustainability messaging.
For instance, Ford includes the use of renewable materials as a key objective in its annual sustainability report:
“The environmental, economic and performance benefits of these durable, plant-based materials include reductions in carbon dioxide (CO2) emission.”
In line with these objectives, a biobased rubber such as EPDM offers another way of integrating renewable materials and further reducing CO2 emissions.
In fact, just using biobased EPDM alone can reduce CO2 emissions by greater than 50%.
Arlanxeo offers six grades of Kelton® eco EPDM: 3050, 8550, 5470, 9950, 6950 and Keltan 0500R.
Most grades include 50% biobased content, while the 5470 has 70%.
Arlanxeo claims that the biocontent of each material can be validated by the ASTM D6866, Carbon-14 test.