Abstract: A flame retardant waterborne polyurethane(PU)was prepared by using N,N-bis(2-hydroxymethyl)aminoethyl phosphonic acid dimethyl ester and toluene diisocynateThe performance of the PU was studied with oxygen index (LOI), thermogravimetric analysis (TG), scanning electron microscopy (SEM)and differential scanning calorimetry (DSC).The results showed that with 15% flame retardant in the PU, the LOI of the PU reached 302%, making the polyurethane from flammable level reduced to flame retardant levelCompared with unmodified waterborne polyurethane, the thermodecomposition temperature of the PU was reduced, but the maximum decomposition rate dropped by 389% and the amount of carbon residue increased by 1075%The surface of carbon residue was compact and smooth without holes, which would be good for separating oxygen and heatPhase separation with increasing flame retardant content showed regular changesWith increasing content of flame retardant, tensile strength increased and elongation at break decreased

Key words: waterborne polyurethane, flame retardancy, phosphorus-nitrogen synergy effects

关键词: 水性聚氨酯, 阻燃, 磷氮协效