Integrated effect of supramolecular self-assembled sandwich-like melamine cyanurate/MoS₂ hybrid sheets on reducing fire hazards of polyamide 6 composites

A novel strategy of using supramolecular self-assembly for preparing sandwich-like melamine cyanurate/MoS₂ sheets as the hybrid flame retardants for polyamide 6 (PA6) is reported for the first time. The introduction of MoS₂ sheets function not only as a template to induce the formation of two-dimensional melamine cyanurate capping layers but also as a synergist to generate integrated flame-retarding effect of hybrid sheets, as well as a high-performance smoke suppressor to reduce fire hazards of PA6 materials. Once incorporating this well-designed structures (4 wt%) into PA6 matrix, there resulted in a remarkable drop (40%) in the peak heat release rate and a 25% reduction in total heat release. Moreover, the smoke production and pyrolysis gaseous products were efficiently suppressed by the addition of sandwich-like hybrid sheets. The integrated functions consisting of inherent flame retarding effect, physical barrier performance and catalytic activity are believed to the crucial guarantee for the reduced fire hazards of PA6 nanocomposites. Furthermore, this novel strategy with facile and scalable features may provide reference for developing various kinds of MoS₂ based hybrid sheets for diverse applications.