INTERACTIONS BETWEEN PHOSPHORUS-CONTAINING AND NITROGEN-CONTAINING FLAME RETARDANTS

A halogen-free, flame-retardant polystyrene containing polyphenylene e ther (PPE) with excellent melt how, impact resistance, and heat resist ance can be obtained through concurrent use of hydroxyphenyl-containin g phosphate (resorcinyl diphenyl phosphate: triphenyl phosphate (TPP)= OH) as phosphorus-containing flame retardant and melamine cyanurate (M C) as nitrogen-containing flame retardant. Investigation of interactio ns between these two flame retardants showed that an intumescent proce ss, which involves the formation of char that swells and foams, occurs upon the burning of this resin composition and lowers the burning sur face temperature by 130 degrees C compared with the resin composition without MC, in which the intumescent process does not occur. The resin composition containing TPP-OH/MC has higher impact resistance than th at containing TPP/MC (TPP: contains no hydroxyl group). Viscoelastic m easurement indicated significant interactions between TPP-OH and MC, i ncluding particularly hydrogen bonding between their hydroxyl and amin o groups, which suggests that TPP-OH acts as a compatibilizer of MC.