Coffee husks residues incorporated into polyurethane foam towards greener material for diesel S10 and S500 removal and recovery

Abstract

Seawater contamination draws concerns due to its effect on the environment and living beings, where oil spillages are highlighted due to their severe impact. Conventional materials to deal with these problems present non-sustainable nature, and thus, new developments are being performed to develop materials that align sorption properties and higher environmental nature. This work prepared PU composite foams with different coffee husk residues (CR) contents for sorption capacity to mitigate oil contamination. Infrared analysis showed that CR promoted harder segments within the PU structure, influencing the composite foam's density. The pore morphology changed from an open-cell to a partial closed-cell structure with a smaller pore size than neat PU, and composites showed a higher contact angle. The samples did not have significant thermal stability and mechanical properties changes compared to neat PU. Besides, all the samples presented strain comparable to neat PU. Sorption tests showed that all the composites presented sorption efficiency exceeding 80 % of removal. PU+ 40 % CR sample stood out as it presents the higher CR content, and the isotherm showed a better fit with the Langmuir model. Additionally, PU+ 40 % CR showed excellent reusability during 14 and 11 cycles of sorption-desorption. • Coffee husk residue revalorization to develop composite foams for oil spillage applications. • CR induced more hard segments in PU, affecting its density and cell morphology. • Composite foams presented higher hydrophobicity, affecting oil sorption. • PU+ 40%CR had reusability of 14 and 11 cycles for Diesel S10 and S500 sorption.