Synthesis of melamine salt of pentaerythritolphosphate as flame retard ant and the application in unsaturated polyester resins

The halogen-free intumescent flame retardant,melamine salt of pentaerythritol phosphate was synthesized from phosphoric acid(P),pentaerythritol(PT) and melamine(M).The product was confirmed by DSC,TG and IR.The results showed the flame retardant had a endothermic peak at 266 ℃ so it had strong heat stabilization.The optimum synthetic conditions based on char residual were as follows:n(P)∶n(PT)∶n(M)=2-2.5∶1∶1.8-2.2,synthetic temperature 100-110 ℃ and curing time 4-6 h.The flame-retardance of unsaturated polyester resins reached a level of UL-V0 when the addition of melamine salt of pentaerythritol phosphate was 18 portions.The flame retardant had the advantages of moderate decomposition temperature and high efficient flame retardancy.