The influence of formulation and technological parameters on the formation of the morphology of open-cell elastomeric materials based on ethylene-propylene-diene rubber (EPDM), intended for the sorption of petroleum products, was investigated. A two-stage foaming technology, providing temporal and temperature separation of gas evolution and vulcanization processes, was employed as the key approach. In the first stage at 120°C and excess pressure, decomposition of the low-temperature blowing agent (sodium bicarbonate, SB) occurred, laying the foundation for an open macroporous structure. In the second stage at 180°C and atmospheric pressure, the main pore growth proceeded via the high-temperature blowing agent (azodicarbonamide) with simultaneous structure fixation by the vulcanization network. It was established that the material's morphology (ranging from quasi-spherical to stochastically trabecular) and the fraction of open pores (from 1 to 91%) are determined by the SB concentration (2–10 phr) and the duration of the first stage (5–9 min). It was shown that the trabecular structure with high tortuosity of pore channels exhibits maximum sorption capacity (up to 17.5 g/g for 15W40 oil) and effectively retains the sorbate due to capillary forces. A tendency of the material to swell in hydrocarbons was identified, which limits its service life during multiple "sorption-pressing" cycles. The developed solution paves the way for the targeted design of structure with predetermined sorption properties.

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