Preparation of hydrophilic reactive polyurethane and its application of anti-water erodibility in ecological restoration

In this work, a novel hydrophilic reactive polyurethane (HRPU) material and HRPU-based composite materials were prepared and used as chemical anti-water erodibility materials for Pisha sandstone. The compressive strength, surface hardness, penetrability and water contact angle were investigated. The results showed that the deformation rate of Pisha sandstone sprayed with HRPU/ethylene-vinyl acetate (EVA) material was approximately 15%, significantly larger than that of other Pisha sandstone samples, while the compressive strength was significantly improved, providing a good penetrability to form a hydrophobic consolidation layer, locking the water in soil. Meanwhile, the micro-morphology of Pisha sandstone was observed by scanning electron microscopy (SEM) images and the water retaining ability of HRPU/ EVA material was discussed in detail. The results showed that the water content of Pisha sandstone sprayed with HRPU/EVA material could reach more than 20%, even after 16 h, which presented an excellent water retaining ability. In addition, the anti-water erodibility of Pisha sandstone with HRPU/EVA was improved to prevent soil and water loss, and provide some feasibility for growing plants. Therefore, it could provide a new material and idea to protect the Pisha sandstone area and other erosion areas.