Intrinsic flame-retardant epoxy resin composite containing schiff base structure with satisfied flame retardancy and mechanical properties

To solve the non-renewable and flammability of traditional epoxy composites, a new type of intrinsic flame-retardant epoxy (VH/GF) composite was fabricated from vanillin-based epoxy resin (VH) and glass fibre (GF). The T5% of VH/GF was higher than that of DGEBA/GF, and CY800 of VH/GF reached above 84 wt.%. VH/GF obtained a limiting oxygen index as high as above 90% and passed UL-94 V-0 rating. Compared with DGEBA/GF, the total heat release, total smoke production, maximal smoke density of VH/GF reduced by more than 72%, 91% and 81%, respectively. The physical barrier of glass fibre and excellent char formation ability of VH endowed VH/GF composite with good condensed phase flame-retardant effect. When the mass ratio of matrix and glass fibre was 5:5, the storage modulus and glass transition temperature of VH/GF were 6.34 GPa and 205 °C, and its tensile strength and elongation at break were 348.36 MPa and 4.01%. This work provides new research insights for bio-based epoxy resin in high-performance fire safety composites.