Fabrication of Triblock Elastomer Foams for Oil Absorption Applications: Effects of Crosslinking, Composition, and Rheology Factors

Oil spill accidents and oil-contaminatedwastewater release fromindustries cause severe environmental pollution, resource waste, andeconomic loss. Thus, there is a dire need for an efficient oil/waterseparation approach to mitigate the challenge. Among the various oil/waterseparation technologies, employing oil-absorbing materials is oneof the most effective strategies. In this work, a highly effectiveelastomer foam based on styrene-ethylene-butylene-styrene(SEBS) and ethylene propylene diene monomer (EPDM) blend was developed.Dicumyl peroxide was employed as a radical initiator for the crosslinkingof the elastomer blend. The crosslinking of the blend significantlyincreased the melt strength of the SEBS/EPDM blend and therefore allowedthem to expand extensively (up to 1200 vol %) with substantial volumeincrease (expansion ratio 12.8-13.1) and created pores withwell-defined structures. As a result, the material exhibited outstandingoil absorption (up to 1030 wt %) due to an enlarged surface area andblend constituents. The incorporation of EPDM and radical-mediatedcrosslinking prevented the dissolution of SEBS in the oil and maintainedthe structural integrity of the foam in the oil, paving the way forrecyclability. Also, the inherent hydrophobicity of employed polymersled to poor interaction with water and, thus, outstanding oil/waterseparation ability of the developed elastomer foams. Additionally,the foaming of triblock polymers, including SEBS, remained largelyunexplored. This study has elucidated the impact of crosslinking andrheological factors on the successful foaming of SEBS.