Effects of nanoclay and flame retardant additives on glass transition temperature, thermal stability and flammability of epoxy composites

Epoxy/nanoclay composites containing ammonium polyphosphate (AP) were prepared by in situ polymerization method using compression molding machine. XRD patterns indicated the formation of epoxy/clay nanocomposites. The glass transition temperature measured by DSC was increased with the addition of nanoclay as well as AP separately in epoxy matrix but decreased when nanoclay and AP added together. On adding AP, the epoxy composites showed early start of degradation but after 400 °C composites became stable and gave high char yield in thermogravimetic analysis. Epoxy composites containing 10% AP accomplished the flame retardant property with V-0 rating in UL-94 test.