Modification of Polyurethane Sponge Based on the Thiol–Ene Click Reaction and Its Application for Oil/Water Separation

A polyurethane (PU) sponge with hydrophobic/oleophilic property was prepared based on the thiol–ene click reaction, which was a simple method with only one step. Photopolymerization was induced through UV light on the sponge surface in a homogeneous solution containing polyethylene glycol diacrylate, pentaerythritol (mercaptoacetic acid) ester, 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone, and octadecyl methacrylate. The as-prepared sponge possessed excellent selective for oil from various types of oil/water mixtures. It also had a high absorption capacity for toluene, >21 times its self-weight, and it had about 20 times its self-weight for vegetable oil, even after five extrusion–adsorption cycles, presenting a good recyclability. It created a new method to prepare oil/water separation sponge.