Effect of Alumina Trihydrate on Intumescent Flame Retardant Polymer Composite Coatings

A charring-foaming agent (CFA) polymer was synthesized via a nucleophile substitution reaction and used in intumescent flame retardant (IFR) coating preparations. The CFA structure was characterized by Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The IFR system was composed of the ammonium polyphosphate (APP) and a foaming agent (CFA). APP and CFA were fixed at 2:1 ratio and different amount of alumina trihydrate (ATH) are loaded into an epoxy resin to prepare IFR coating compositions. The TGA results showed that the addition of ATH greatly increased the char residue percentage of the coatings at 800 degrees C. The UL-94V data indicated that the V-0 ratings were obtained with the addition of ATH into coatings. The cone calorimeter data showed that the peak heat release rates (PHRR) and total heat releases (THR) of the coatings remarkably decreased with the increase of ATH loading. The incorporation of ATH into epoxy/IFR enhanced the thermal stability and incombustible behavior of the coating system.