The natural compound phytic acid is widely present in plant materials, especially in seeds and grains, but is not digestible by non-ruminant animals such as pigs, poultry and humans.
Phytic acid was reacted with urea to generate ammonium phytate. This was applied as a PIN flame retardant for woven cotton fabric (115 g/m2) by two cycles of immersion for ten minutes in a water solution with dicyandiamide catalyst then pressing (padding), curing at 170°C, rinsing and drying. The catalyst enables grafting of the ammonium phytate into the cotton fibres through covalent bonding (“reactive”). This application increased the Limiting Oxygen Index (LOI) of the cotton fabric from 18% to 43% (30% after 30 laundry cycles, 25% after 50) and reduced vertical char length from 300 mm by 90%.
“A plant-based reactive ammonium phytate for use as a flame-retardant for cotton fabric”, Y. Feng et al., Carbohydrate Polymers, 2017 http://dx.doi.org/doi:10.1016/j.carbpol.2017.06.129