Improving the Hydrophilicity of Flexible Polyurethane Foams with Sodium Acrylate Polymer

Hydrophilic, flexible polyurethane (FPU) foams made from Hypol prepolymers are capable of retaining large amounts of water and saline solutions. The addition of different catalysts and surfactant agents to Hypol JM 5008 prepolymer was assayed to obtain a foam with good structural stability and elasticity. The combination of three catalysts, stannous octoate and two amine-based ones (Tegoamin 33 and Tegoamin BDE), and the surfactant Niax silicone L-620LV allowed to synthesize a foam with a homogeneous cell size distribution, exhibiting the highest saline absorption capacity (2.4 g/gram of foam) and almost complete shape recovery, with up to a 20% of remaining deformation. Then, superabsorbent sodium acrylate polymer (PNaA) was added to the FPU foam up to 8 pph. The urine absorption capacity of the foam was increased about 24.8% by incorporating 6 pph of PNaA, absorbing 17.46 g of saline solution per foam gram, without any negative impact on the rest of the foam properties. All these properties make the synthesized foams suitable for corporal fluids absorption applications in which elasticity and low-density are required.