Sustainable polyurethane nanocomposite foam from waste poly(ethylene terephthalate): preparation, thermal stability, and flame retardancy

In this work, we proposed and synthesized sustainable nanocomposite polyurethane foam (PUF) derived from waste poly(ethylene terephthalate) (PET), reinforced with nano ZnO and incorporating aluminum hydroxide (ATH) as a flame retardant. Chemical structure of oligodiol obtained from the glycolysis of waste PET by diethylene glycol and ZnSO4.7H2O catalyst under microwave irradiation was confirmed by FTIR and 1H-NMR and continuously product of that was used to prepare PUF nanocomposite material. The density of the PUF decreased from 58 to 35 g/cm3 by the addition of ZnO nanoparticles, which are suitable for lightweight and insulation applications. In addition, the incorporation of ATH is indispensable to enhancing the flame retardancy of the PUF nanocomposites with UL-94 (HB) at 100 php ATH loading and UL-94 (VB) V-0 at 150 php ATH loading, simultaneously enhancing the mechanical properties of PUF/ZnO/ATH nanocomposites. The outcomes not only met the fire safety requisites, light-weight, and high mechanical properties for polymer nanocomposite material applications in construction but also incorporated a substantial proportion of discarded PET bottles sourced from associated industries.

Graphic abstract

The PUF nanocomposite foam derived from waste PET has high mechanical property and excellent flame-retardant performance to create a sustainable recycling polymer material and improve waste management.