Readily recyclable, high-performance catalyst-free tung oil-derived vitrimer and carbon fiber reinforced composites

Abstract Carbon fiber-reinforced composites (CFRCs) derived from thermosetting resins and carbon fibers are widely used in aerospace, civil engineering, and sport equipment. However, CFRCs have an undegradable resin matrix and nondestructive recycling of carbon fibers. To address this dilemma, we prepared readily recyclable, high-performance catalyst-free tung-oil-derived vitrimer and CFRCs from tung-oil-based acid curing agents (named as TTMA) and bisphenol A epoxy resin (DGEBA) or 4,4'-methylenebis (N, N-diglycidylaniline) (TGDOM). DGEBA/TGDOM-TTMA networks with plentiful ester bonds, hydroxyl groups, and tertiary amine without extra catalyst can undergo topological rearrangement of cross-linked networks via dynamic transesterification reactions at high temperature. Thus, the epoxy resin matrix of CFRCs has excellent mechanical property, thermostability, and can be easily reprocessed, self-healed, and degraded at elevated temperatures. TGDOM-TTMA has good stress relaxation properties owing to the high concentrations of hydroxyl and tertiary amine. What's more, carbon fibers can be completely recycled from CFRCs using the ethanolamine via amidation reaction, where the recycled carbon fibers maintained nearly 100% of the mechanical properties from the virgin samples. The theoretical implications of this work lie on offering a sustainable and convenient strategy for designing readily recyclable and high-performance CFRCs.