A synergistic flame retardant of glycosyl cross-linking boron acid and ammonium salt of phytic acid to enhance durable flame retardancy of cotton fabrics

In the present research, a glycosyl cross-linking coordination chelate flame retardant was designed to enhance durable flame retardancy of cotton fabrics. It was a halogen-free, non-formaldehyde boron acid and phytic acid ammonium salt synergistic flame-retardant system. The flame retardancy and durability of flame retardants prepared by different saccharides were investigated. Results showed that raffinose was the best cross-linking reagent compared with the other monosaccharides and oligosaccharides. The raffinose as cross-linking reagent prepared glycosyl cross-linking boron acid and ammonium salt of phytic acid flame retardant (r-GBAP) (100 g/L) can obtain the shortest char length of 56 mm and the largest limiting oxygen index (LOI) value of 37.4%. A lower r-GBAP concentration can get good flame retardancy, due to adopt the three curing cycles process. FTIR, XPS, LOI, TG and SEM testing and characterization techniques were used to analyze and research the flame retardancy, durability, thermal oxidation stability and flame-retardant mechanisms of r-GBAP and the treated cotton fibers.