Flame-retardant effect of tris(2,3-dibromopropyl) phosphate on polystyrene

The flame-retardant effect of tris(2,3-dibromopropyl) phosphate (TBPP) on polystyrene was investigated using thermogravimetry, infrared spectroscopy, gel permeation chromatography, and electron spectroscopy for chemical analysis (ESCA). The following results and conclusions were obtained: (1) The addition of TBPP (about 3 wt%) to polystyrene had flame-retardant properties. (2) The addition of TBPP resulted in lowering the temperature of the burning surface and the amount of volatile products. TBPP increased the thermal stability of polystyrene. (3) TBPP inhibited oxidative attack on polystyrene. In the presence of TBPP the formation of peroxide groups at the burning surface was inhibited. It is inferred that this inhibition decreases the evolution of flammable fuels from the burning surface and contributes flame-retardant properties. There is a lesser possibility that TBPP acts as a physical barrier that limits oxygen access. At present there is no idea of why TBPP inhibits thermoxidative reactions of polystyrene.