A novel green IFR system: Design of a self-assembled peanut shell-based flame retardant and its fire performance in EP

Carbon derived from peanut shell (CPS) with 2D structure has been proved to own sufficient thermal stability and is a promising flame retardant (FR) additive for EP in our previous work. To further explore the feasibility of implementing CPS into the intumescent fire retardant (IFR) system, a novel green IFR system was first proposed in this study. Environmental-friendly chemicals phytic acid (PA) and melamine were self-assembled on the carbon's surface through the hydrothermal method. Cone calorimeter test results reveal that 3 wt% loading of the proposed IFR reduces total heat release (THR) by 38.8 % and total smoke release (TSR) by 31.3 %. What's more, the char residue grows significantly, from 5.8 % to 14.3 %. The fire retardancy mechanism was also studied. For the gaseous phase, the release of inert gas products from melamine prevents volatile decomposition products into the combustion zone. In terms of the solid phase, a synergistic barrier effect is provided by 2D structure of peanut shell derived carbon and the intumescent residue with a compact exterior layer, protecting the underlying polymer matrix. This green IFR system provides better fire performance, which can be a potential alternative for EP and extend its application.