A facile and green approach for the surface coating of phosphorus–silicon functionalized graphene oxide to improve flame retardancy of polyurethane foam

evolution and a high char residue of 52%, indicating significant suppression of volatile fuel and smoke hazards. This fire protection is attributed to the formation of a dense phosphosilicate protective layer, which provides a robust barrier effect in both gas and condensed phases. Additionally, the coating treatment remarkably enhanced the mechanical performance of the foam. The compressive strength of PUF/FGO increased by 152% (1.34 MPa) compared to pristine PUF, as the FGO effectively infiltrated structural defects and reinforced the cellular framework. Consequently, FGO demonstrates superior efficacy over GO in providing a multifunctional solution for high-performance, fire-safe PUF.