Development of polyamide12 composite foam by supercritical CO2: The effect of flame retardants on foaming behavior and properties

In this work, aluminum phosphonate (AlPi) and melamine cyanurate (MCA) were used as flame retardants, a modified polyamide12 (PA12) foam with excellent flame retardancy was prepared by supercritical CO2. The effects of different proportions of flame retardants on the volume expansion ratio were explored. Then the effect of different flame retardants on PA12 foaming was studied at the largest expansion ratio (at a density of 0.08 g/cm3). The results showed that AlPi and MCA could promote heterogeneous nucleation and increase the volume expansion ratio of PA12 foam. The ignition time of the PA12 foam was doubled in the cone calorimeter test and the total heat release was halved. In addition, the flame retardant performance reached HF-1.