Readily Recyclable, Auto-Catalyzed Tung Oil-Derived Vitrimers and Carbon Fiber-Reinforced Composites

The high strength and durability of carbon fiber-reinforcedcomposites(CFRCs) have made them a popular choice in aerospace, civil engineering,and sports equipment. However, the non-degradable resin matrix andnon-destructive recycling of carbon fibers present a challenge fortheir sustainability. To address this issue, we have developed a newtype of CFRCs that are readily recyclable and high-performing, usingan auto-catalyzed tung oil-derived vitrimer and acid curing agents(TTMA) in combination with bisphenol A epoxy resin (DGEBA) or 4,4 '-methylenebis (N,N-di glycidylaniline) (TGDOM).The DGEBA/TGDOM-TTMA networks contain abundant ester bonds, hydroxylgroups, and tertiary amine, which can undergo dynamic transesterificationreactions (DTER) at high temperatures, leading to topological rearrangementof cross-linked networks. This results in an epoxy resin matrix withexcellent mechanical properties, thermostability, and easy reprocessing,self-healing, and degradation at elevated temperatures. Moreover,the TGDOM-TTMA exhibits good stress relaxation properties due to thehigh concentrations of hydroxyl and tertiary amine. Additionally,we have found that carbon fibers can be completely recycled from CFRCsusing ethanolamine via amidation reaction, with the recycled carbonfibers maintaining nearly 100% of the mechanical properties of thevirgin samples. This study offers a sustainable and convenient strategyfor designing readily recyclable and high-performance CFRCs, withimportant implications for the future of composite materials.