EPDM rubber is a thermoset elastomer or rubber material. It has a fairly low density and the highest heat capacity among rubber materials. The graph bars on the material properties cards below compare EPDM rubber to other rubber materials (top) and the entire database (bottom).
Material Reference. The chart below is intended to help in the material selection stage of designing rubber parts / products. Rubber compounding is a very broad and technical field, since basic rubbers or elastomers are mixed with various chemicals and ingredients (and even with each other) to obtain desired physical properties.