A simple method enabled production of a novel nitrogen phosphorus salt from ethylene glycol, phosphoric acid and urea, without solvent, generating AEGDP (ammonium ethyl glycol diphosphoric acid).
This was applied to cotton fabric (133 g/m2) by aqueous immersion, padding and rinsing, with dicyandiamide catalyst. Treated cotton showed 96% lower peak heat release, was self-extinguishing and gave significantly lower emissions of flammable volatile gases during fire tests (hydrocarbons, carbonyls, ethers). These effects are identified as resulting from char was progressively reduced after washing but remained significant after 30-50 laundry cycles. The treatment showed no significant effect on serviceability of the fabric.
“Facile synthesis of an eco-friendly nitrogen–phosphorus ammonium salt to enhance the durability and flame retardancy of cotton”, Y. Jia, et al., J Materials Chemistry A, issue 20, 2017 http://dx.doi.org/10.1039/c7ta01106g