Superior radical scavenging and catalytic carbonization capacities of bioderived assembly modified ammonium polyphosphate as a mono-component intumescent flame retardant for epoxy resin

•An all-in-one intumescent flame retardant (APP@ATNi) was synthesized by using biobased resources for epoxy resin.•APP@ATNi exhibits excellent fire resistance and smoke suppression performance.•APP@ATNi can form hydrogen bonds with the EP matrix and contribute to improve the mechanical properties of the composites.•APP@ANTi as an oxygen radical scavenger can reduce the release of toxic and flammable gases during combustion.