Flexible polyurethane foams surface-modified with FeOOH for improved oil-water separation and flame retardancy

Abstract

In this work, the flexible polyurethane foam modified with FeOOH (FPU/FeOOH) was successfully fabricated by hydrothermal method with ferric chloride hexahydrate and urea as raw materials. FPU/FeOOH foams were characterized by X-ray diffraction (XRD), Scanning electron (SEM), X-ray energy dispersive spectroscopy (EDS) and Contact angle (CA), showing a large amount of FeOOH nanoparticles were uniformly distributed on the surface of FPU foams. The introduction of FeOOH significantly boosted the hydrophobicity and oleophilicity of FPU foams, and the maximum adsorption capacity for various oil products and organic solvents had achieved 44 times of its own weight. Moreover, the modified FPU foams still had excellent reusability and stability. Not only that, the flammability of FPU/FeOOH foams was estimated by cone calorimeter test (CCT) and direct combustion test, the values of peak heat release rate (PHRR), total heat release (THR), peak smoke production rate (PSPR) and total smoke production (TSP) decreased dramatically, indicating the introduction of FeOOH nanoparticles remarkably boosted the flame retardant property of FPU foams. Therefore, due to its facile fabrication technique, excellent absorption performances, reusability and flame retardancy, the FPU/FeOOH foams hold great promise for potential applications in oil/water separation.