Synthesis and application of a novel waterborne polyurethane emulsion for sand fixation

Desertification is one of the severe ecological and environmental issues in the world today. Sand fixation against wind erosion is an effective solution to the problem. In the present study, a novel waterborne polyurethane emulsion was prepared as a sand-fixing agent. Lignin and polylactic acid were incorporated as a chain extender and soft segments, respectively. The structure, viscosity and thermal stability of the polyurethane emulsions were studied by FTIR, rheological testing and differential scanning calorimetry (DSC). The sand fixation properties of the waterborne polyurethane were evaluated in terms of the water retention, compressive strength, thermal stability and anti-wind erosion ability of sand crusts formed by spraying the emulsion on sands. With the increase of lignin content, both the water retention and compressive strength increased with the highest values of 39.22% and 1.13 MPa, respectively. All the sand specimens treated by the waterborne polyurethane presented good thermal stability and wind erosion resistance.