Self-extinguishing low-nitrogen nitrocellulose based on synergistic effect of dimethyl methylphosphonate
and long-chain chlorinated paraffin
A series of flame retardant low-nitrogen nitrocelluloses (FR/NCs) containing different weight ratios of dimethyl methylphosphonate (DMMP) and long-chain chlorinated paraffin (CP) were directly prepared by blending method, and the burning behaviors, thermal and mechanical properties, pyrolysis process and char residues were investigated.The results showed that (DMMP/CP = 8/2)/NC at a total flame retardant loading of 17 wt % displayed the self-extinguishing behavior following a multi-flame retardancy mechanism with synergistic effect that includes gas-phase effects, endothermic effectsand slightly condensed-phase effects of flame retardancy. In addition, the tensile properties of the (DMMP/CP = 8/2)/NC revealed a synergistic plasticization effect, which could enhance the flexibility of NC. This new system provided a reference for improving a safety storage and widely application of NC in the future.