Design of inherent fire retarding and degradable bio-based epoxy vitrimer with excellent self-healing and mechanical reprocessability

Epoxy resins possess poor flame retardancy and have difficulty in both recycling reprocess ability which largely limit their application. Herein, two vanillin-based epoxy monomers, shorted as VAD-EP VDP-EP, containing imine bonds inherently fire retarding phosphorus elements, were synthesized via situ condensation reaction with DDM addition DOPO, followed by the epoxidation epichlorohydrin. vitrimer materials then cured D230 diamine hardener adjusting proportion of VDP-EP monomer. When mass ratio was 8:2, A8P2-D230 reached UL-94 V0 rating LOI value 27.0% only 0.66% content, this behavior ascribed to condensed phase free radical scavenging mechanisms. 7:3, tensile strength elastic modulus A7P3-D230 75.5 MPa 2.5 GPa, respectively, i.e. 48.6% 18.8% higher than A10P0-D230 sample. Meanwhile, material showed high stress relaxation rate, due presence dynamic topological crosslinking network. As a consequence, exhibited excellent self-healing capability, reprocessability degradation behaviors. The biobased used prepare carbon fibers (CFs) reinforced composites, results that CFs can be completely recycled. Interestingly, recycled maintain unchanged chemical structure, mechanical properties morphology original CFs.