Preparation of a novel hydrophobic polyurethane foam and its oil adsorption properties

Hydrophobic polyurethane foam (PU) with high oil absorption capacity was synthesized. Poly-(tetrahydrofuran triol) (PTHF-T) and poly-(tetrahydrofuran glycol) (PTHF-G/PTMG) were first synthesized using glycerin or water as the initiator, and one of the synthesized materials was reacted with polyether polyol (PPO-T) and toluenediisocyanate (TDI) to prepared the PU foam. The effects of raw material ratio, degree of functionality and molecular weight (M_w) of polytetrahydrofuran on oil adsorption capacity, and the toluene selective absorption ability in a toluene-water system were investigated. The results show that the optimal raw material ratio for the best oil absorption is m (PTHF-T): m (PPO-T): m (triethylenediamine): m (stannous octoate): m (foam stabilizer): m (triethanolamine): m (deionized water): m (TDI) = 15: 85: 0.8: 0.24: 1.5: 2.4: 5.0: 40 (the molecular weight of PTHF-T and PPO-T are about 4400). The oil absorption capacity can reach up to 69.1 g·g^-1 for carbon tetrachloride, 51.1 g·g^-1 for dimethylbenzene, 50.5 g·g^-1 for toluene, 41.0 g·g^-1 for ethanol and 29.8 g·g^-1 for diesel oil. In toluene-water system, the selective oil absorption capacity is 51.0 g·g^-1 for toluene, which is equal to that in the pure toluene system. There is no change on the oil absorption capacity when the material is used repeatedly for 8 times. Therefore, the polyurethane foam can be used for oil spill recovery treatments.