In this study, the crosslinked ethylene?propylene?

diene monomer (EPDM) foams were prepared by batch foaming

using compressed CO2 as the blowing agent. The various

crosslinking structures, i.e., the local primary crosslinking structure,

the micro-crosslinking structure, and the full crosslinking structure,

were generated by adjusting the loading of the crosslinking agent.

The models were established to illustrate the fundamental

influences of crosslinking structures on the evolution of cell

morphology. EPDM-0.2B with 0.2 parts per hundred of rubber

(phr) loading of the crosslinking agent had the micro-crosslinking

structure, which improved the foamability of EPDM significantly.

The foaming temperature window was broadened from 40?80 to

100?200 °C, and the expansion ratio was increased from 5.6 to 7.1

compared with pure EPDM. Meanwhile, the structure endows the EPDM-0.2B foam with improved creep resistance, increased

thermal stability, and a melt-recycling ability. The EPDM foam with the full crosslinking structure exhibited better creep resistance

and thermal stability, but the structure spoiled its melt-recycling ability significantly.