Synergistic Effect of Sodium Polymetaphosphate-Urea on the Flame-Retardancy Imparted to a Polyester Fabric

摘要

The synergistic effect between sodium polymetaphosphate(Calgon)and urea on the flame-retardancy of a polyester fabric(plain construction weighing 160 g/m2)is described in this study.The laundered bone-dried weighed specimens were impregnated with suitable concentrations of individual aqueous sodium polymetaphosphate(Calgon)or urea solutions and some sets were impregnated with appropriate admixed solutions of both chemicals.A vertical flammability test was then carried out.An acceptable synergistic effect was obtained using an admixed bath containing 0.4 molar sodium polymetaphosphate and 4.0 molar urea solutions for imparting flame-retardancy to a polyester fabric.The optimum weight of the mixture needed to impart flame-retardancy was about 36.52g anhydrous additives per 100g fabric.The results obtained are in favour of "phosphorus-nitrogen synergism" required to retard the flame.They comply with "chemical theory," "gas theory," and "condensed phase retardation."