highly fire resistant composites or laminates particularly applicable as structural components in aircraft , e . g . in the engine nacelle , as part of the acoustic panel - fire wall structure , and capable of withstanding a 2 , 000 ° f . flame temperature , comprising incorporating an additive in the form of a polymeric phosphorylated amide , into a resin , e . g ., a polyimide or an epoxy resin , such additive being soluble in the resin . the resulting resin containing the additive is then applied to or impregnated into a substrate such as glass fiber cloth or graphite fiber , to form a composite structure which is then cured . the resulting cured composite when subjected to high temperatures of the order of , e . g ., a 2 , 000 ° f . flame temperature , forms a resin char of reduced thermal conductivity which holds the fibers of the laminate together and maintains the structural stability and integrity of the laminate .