Synthesis and characterization of a novel polyphosphamide with enhanced phosphorus-nitrogen content

A novel polymer with enhanced phosphorus-nitrogen content-poly(piperazine spirocyclic pentaerythritol bisphosphonate) (PPS) was synthesized, which was prepared by solution polycondensation from pentaerythrttol, piperazine, and phosphorus oxychloride. The structures and the thermal stability of the compound were characterized by ¹H-NMR, ³¹P-NMR, IR, elemental analysis and TGA. Analysis results show it has effective thermal stability. The initial decomposition temperature of polyphosphamide is around 326°C, and char yield is 46%. It belongs to a class of materials known as intumescent flame retardant. The inherent viscosity of the polyphosphamide is 0.19 dL/g. The result of DSC shows that the PPS do not have glass-transition temperature.