The thermal stability and flame retardant effect of Al(OH)3 on NBR containing intumescent flame retardant

This research studies the effect of aluminum hydroxide (ATH) on the thermal stability and flame retardant properties of nitrile rubber (NBR) composites containing IFR (Intumescent flame retardant). Differential scanning calorimetry (DSC), thermogravimetric analysis (TG), and gas chromatography-mass spectrometry (GC/MS) were used to determine that adding 2 wt % flame retardant synergist ATH to NBR/IFR composites enhances the thermal stability of the composite and improves the charring effect of the IFR-containing composite. The flame retardancy of the composite is enhanced when 2 wt % ATH flame retardant synergist is added. The study suggests that the improved thermal stability and flame retardancy of the composite containing ATH may be due to the reaction of ATH with ammonium polyphosphate, which generates phosphate and increases the particle size of ATH. Additionally, this reaction produces high-temperature resistant inorganic compounds such as Al(H2PO4)(3), which can easily connect ATH particles together to form aggregates, resulting in a layered char structure after combustion.