Sodium tri-polyphosphate in combination with pomegranate rind extracts as a novel fire-retardant composition for cellulosic polymer

Abstract

For the first time, a mixed formulation of the sodium tri-polyphosphate (STPP) and the pomegranate rind extract (PRE) has been imparted to the cotton fabric to make it flame-retardant. It was found that the control, 3% STPP and PRE-treated cotton fabric showed the limiting oxygen index (LOI) value of 18, 21 and 26%, respectively, and completely burnt within 80, 120 and 420 s, respectively, in the vertical flammability test. On the contrary, (PRE + 2% STPP)-treated cotton fabric showed the LOI value of 35% with a specific char length of 30 mm. Thermo-gravimetric analysis of the control, PRE- and the 3% STPP-treated cotton fabric showed only 1–2% remaining char mass at 550 °C, whereas the (PRE + 3% STPP)-treated fabric registered the char mass retention of more than 10% at the said temperature. Cone calorimetric data showed that the peak heat release rate for the treated fabric has been reduced dramatically compared to the heat release value of the control cotton fabric.