In situ growth of polyphosphazene particles on molybdenum disulfide nanosheets for flame retardant and friction application

Abstract Herein, polyphosphazene nanoparticle (PPN) functionalized MoS 2 nanosheets have been successfully fabricated through a novel two-step method, involving a simple ball milling of bulk MoS 2 powders to acquire exfoliated MoS 2 nanolayer, followed by high temperature polymerization to achieve MoS 2 @PPN nanohybrids. The incorporation of P and N atoms could efficiently reduce the stacking of MoS 2 nanolayers and form large number of active sites. It is noted that introducing well-characterized MoS 2 @PPN nanohybrids significantly improve the flame retardancy of epoxy resin (EP), i.e., 30.7% and 23.6% reductions in peak heat release rate and total heat release, respectively. The friction coefficients testing results reveal that the EP/MoS 2 @PPN1.0 composite exhibits the lowest friction coefficient value and volume wear rate. The excellent properties of these EP composites result from synergetic coupled effect between PPN and MoS 2 ultrathin nanosheets, as well as improved interface interaction between MoS 2 @PPN and EP matrix.