Phosphorus-nitrogen Flame Retardant Waterborne Polyurethane/Graphene Nanocomposite for Leather Retanning

We demonstrate a facile and green approach to preparephosphorus-nitrogen containing waterborne polyurethane/graphene nanocomposite (PN/G-WPU) as flame-retardantretanning agent for leather. The PN/G-WPU was synthesized bycovalently embedding phosphoramidate-based diol intopolyurethane chain, followed by emulsification with grapheneoxide (GO) aqueous solution and in-situ reduced with hydrazinehydrate. The structure and emulsion stability of prepared PN/GWPUwere characterized, and the physical mechanical propertiesas well as the flammability of resulting leathers were investigated.The results indicate the good dispersion and strong interfacialinteraction of graphene with polyurethane matrix, whichfacilitates the PN/G-WPU penetrating into leather fibers. ThePN/G-WPU retanning agent can effectively improve thecomprehensive performance of resultant leather such ashydrothermal stability, physical-mechanical properties, flameretardancy and smoke suppression performance. Accordingly,our method might provide an alternative strategy formanufacturing high-performance leather.