Synthesis of a high-performance novel single-molecule intumescent flame retardant for cotton fabric

A novel water-soluble flame retardant, ammonium salt of mono (o-phenylenediamine) phosphoric citrate (AMOPPC), was synthesized and characterized. The AMOPPC was applied to cotton fabric (CF) to enhance its flammability and thermal stability properties.1H NMR and FTIR data confirmed the formation of the AMOPPC salt. Thermal analysis data showed an improvement in the thermal stability of treated CF at high temperatures compared to untreated CF, and char residue was significantly increased at 750 °C. Vertical flammability test (VFT) data indicated that the treated samples achieved self-extinguishing. The limiting oxygen index (LOI) of the treated CF was raised to 42.5% at 19% weight gain, while the cone calorimeter data showed a reduction of 73.7% in the peak of heat release rate (pHRR) and 51.5% in the total heat release (THR).