Abstract

Aluminium hydrogen phosphite (AHP) was synthesized in order to investigate their flame retarding performances for unsaturated polyester (UP). AHP and triphenyl phosphate (TPP) flame retardants were studied to increase fire resistance and thermal stability of materials. UL 94HB rating is achieved at 15 wt% AHP - 15 wt% TPP loading. Sample with 30 wt% loading of AHP has the burning rate slower than that of neat UP. The incorporation of FR increases the flame retardant properties as well as the amounts of charred residues protecting the mixture from further degradation. This assertion can be accepted when observing that the char yield of UP/FR mixtures at 500-650 oC is much higher than that of neat UP. The char layer may limit the amount of fuel available and insulate the underlying polymer from the flame and, thus, make further degradation more difficult.