AirBoss of America Corp.’s innovative thinking has again brought the company to the forefront of heat-resistant rubber technologies.
As the space for the engine compartment continues to decrease in modern cars for functional and aesthetic reasons, hotter engines are increasingly becoming the norm, which ultimately restricts the amount of rubber materials that can be used.
Silicone and fluoroelastomers have proven to be effective heat resisters from their strong Si-O and C-F bond in their chemical structures, but their high price and processing costs have made them economically less than ideal.
Ethylene–propylene–diene terpolymer (EPDM) as one of the fastest growing synthetic elastomers. Its thermal stability — among many other qualities — has made it the go-to elastomer in many automobile sectors. In terms of sales volume, it’s the top elastomer of choice among non-tire elastomers.
Still, even with its strong resistance to oxidation, ozonation and weathering, the capability of operating for an extended service life without losing functionality at high temperatures is the most critical unmet need for EPDM systems.
Until now.
AirBoss has introduced the HeatBoss EPDM. It’s the next generation of a high heat resistant EPDM compound, prepared by novel formulation design using EPDM polymer with a selected 3rd diene monomer and peroxide cure system. The resultant formulation demonstrates superior heat resistance to that of normal EPDM compounds, cured by either sulfur or peroxide.
After being aged at 350 F for 672 hours, the HeatBoss EPDM showed only 53% loss in elongation at break, 30% decrease in tensile strength, along with a 7-point increase in hardness.
Those numbers are comparable to that of a typical silicone rubber used in automotive muffler hanger application. However, EPDM showed better initial dynamic and mechanical properties than the silicone, which means the HeatBoss EPDM can match the performance of the silicone after aging.
The HeatBoss EPDM showed excellent resistance to ozone and oxygen attack at higher temperatures as well. All put together, the HeatBoss EPDM can be qualified for type E applications per SAE J200 or ASTM D2000.
HeatBoss EPDM can also be formulated to possess similar processability to the silicone, but at a 50-60% lower cost, which makes the HeatBoss EPDM an ideal alternative for silicone in muffler hanger application and potentially for others that require Grade E elastomers.