Fireproof behavior of polyurethane foam based on waste poly(ethylene terephthalate) using aluminum hydrogen phosphonate flame retardant

Poly(ethylene terephthalate) is a widely used polymer in the blow molding bottles, electron industry, texiile industry and can be recycled to synthesize new materials such as polyurethane foam (PUf) and unsaturated polyester (UP). One of them, PUf has many desirable properties such as low thermal conductivity, low density, excellent dimensional stability, high strength-to-weight ratio, low moisture permeability and low water absorption. However, PUf is a highly flammable material. In this study, aluminum hydrogen phosphonate (AHP) was synthesized in order to investigate their flame retarding performances for PUf. UL-94 V-1 was obtained at 15 phr loading of AHP. The incorporation of flame retardant increased the fireresistant property of PUf. In addition, other properties such as density, foam structure, and water and moisture absorption were also investigated.