Thermal stability and combustion properties of polyurethane foam modified with manganese phytate and expandable graphite

Manganese phytate (MnPa) was prepared and synergistically combined with expandable graphite (EG) flame retardant modified polyurethane foam (PUF). Utilizing thermogravimetric (TG), pyrolysis kinetic analysis, CONE analysis, smoke toxicity analysis, limiting oxygen index (LOI), and UL-94 horizontal combustion test procedures, the thermal stability and combustion parameters of the modified PUFs were examined. The flame retardancy and smoke suppression of the modified PUFs were analyzed based on the heat release rate (HRR), total heat release (THR), smoke production rate (SPR), and total smoke release (TSR). The results showed that MEPUF3 had the highest thermal decomposition rate temperature, initial thermogravimetric temperature, and activation energy (E). It was shown that MEPUF3 had the lowest HRR of 17.68 kW/m², the lowest THR of 1.15 MJ/m², the lowest SPR of 0.0046 m²/s, the lowest TSR of 19.58 m²/m², the lowest Ds of 32.1, the highest transmittance of 57.7%, and the highest LOI of 23.0%. The present study showed that MEPUF3 possessed good thermal stability and flame retardant properties, which provided useful references for subsequent phytate and EG-modified PUFs.