Miscanthus floridulus-based intumescent flame retardant by green self-assembly for fully biological EP composites with commendable flame retardancy, smoke suppression and mechanical properties

The design of fully biological epoxy resin (EP) composites with high performance is highly desirable driven by green and sustainable development due to their renewable and sustainable nature. Herein, an efficient intumescent flame retardant based on Miscanthus floridulus (MF-based IFR) was devised for bio-epoxy composites by a green self-assembly method. The resulting composites with 15 wt% MF-based IFR demonstrated outstanding flame retardancy, effective smoke suppression, and favorable mechanical properties. The enhanced flame retardancy demonstrated the V-0 rating of UL-94 and the 26.4 % of limiting oxygen index (LOI) due to the dual-phase flame-retardant mechanism. Compared to pure EP, the EP composite with 15 wt% MF-based IFR exhibited reductions of 71.90 %, 61.85 %, 55.0 %, and 60.94 % in peak heat release rate (pHRR), total heat release rate (THR), smoke release rate (SPR), and smoke growth rate (TSP), respectively. Additionally, compared to unmodified MF, the composites with 15 wt% MF-based IFR displayed increasing of 3.35 %, 11.26 %, and 10.24 % in tensile, bending, and impact strengths, respectively, attributed to the enhanced interface compatibility. This study provides a straightforward, cost-effective, and efficient strategy for producing fully bio-based epoxy composites with high performance, expanding their potential applications.