Enhanced flame retardancy and mechanical properties of waterborne polyurethane based on the phosphorus and nitrogen containing polybutadiene acrylonitrile

To further improve fire resistance of waterborne polyurethane, the macromolecular intumescent flame retardant (APBDH) was designed and prepared from 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO), 4‐aminothiophenol, benzaldehyde, and hydroxyl‐terminated polybutadiene acrylonitrile (HTBN). Then, it was incorporated into waterborne polyurethane (WPU) to preparing flame retarded WPU (FR‐WPU). TGA results suggested that the incorporation...