Fabrication of porous thermoplastic polyurethane monoliths via thermally induced phase separation for oil/water separation

The preparation of polyurethane-based porous materials from waste sources for the selective separation of oil from contaminated water has attracted significant attention. In this study, a hydrophobic and oleophilic porous thermoplastic polyurethane (TPU) monolith was fabricated via a thermally induced phase separation (TIPS) method. The optimal preparation conditions, determined through orthogonal experiments, were as follows: a TPU concentration of 2.8 g per 40 mL of solvent, a solvent ratio of 1,4-dioxane to water at 11:1 (v/v), and a freezing temperature of −20 °C. The resulting TPU monolith exhibited excellent adsorption performance, capable of absorbing oils and organic solvents up to 6–55 times its own weight. Moreover, it maintained stable adsorption capacity under harsh conditions, including exposure to strong acids, strong bases, and a wide temperature range. The material also demonstrated effectiveness in removing trace organic pollutants from oil-in-water emulsions.