Effect of Thermal Aging on Mechanical Properties of EPDM Rubber

EPDM rubber was exposed to an accelerated thermal aging environment produced by an air-circulating oven. The changes of morphology, mechanical properties of EPDM were monitored by scanning electron microscope (SEM), tensile/compressive testing. Crosslink density of EPDM was measured by the solvent swell method. The results showed that many cracks and voids appeared on the surface of EPDM with the exposure time. The aging process proceeded predominantly via crosslinking. The tensile strength increased with increase in crosslink density up to a maximum and thereafter decreased with further increase in crosslink density.