Effect of prepared barium phytate on thermal stability and combustion properties of flexible polyurethane foams

Flame retardant barium phytate (PABA) was prepared by phytic acid and barium carbonate. PABA was used to modify flexible polyurethane foam (FPUF) by “one-step method” to obtain composite FPUF-PABA. The effects of PABA on the thermal stability and combustion properties of FPUFs were studied by smoke density (Ds), cone calorimeter (CONE), thermogravimetric analysis (TGA), and pyrolysis kinetic analysis. The results indicated that the addition of PABA improved the flame-retardant properties of the modified FPUFs. The CONE results showed that PABA significantly reduced the PHRR and total heat release (THR) of FPUF, and FPUF-PABA15 had the lowest PHRR (44.69 kW/m²) and THR (2.49 MJ/m²). TGA showed that FPUF-PABA15 had maximum residual masses of 27.14%, 26.99%, 28.61%, and 27.25% at four heating rates, respectively. Integral programmed decomposition temperature analysis found that FPUF-PABA15 also had the highest decomposition temperature, 225.56, 210.54, 148.83, and 162.13°C at four different heating rates. At the same time, the computational activation energy of FPUF-PABA15 was also the highest, at 133.30, 140.46, and 129.46 kJ/mol, respectively. Ds indicated that FPUF-PABA15 had the best smoke suppression performance, Ds decreased by 2.47 and light transmittance increased by 2.33%. The current results provide a better formulation for bio-based flame retardant-modified FPUF.