Synthesis of Cardanol-Based Thermosets Integrated Thermal, Mechanical, and Degradation Performance and Its Application in Carbon-Fiber-Reinforced Composites

Petroleum-based thermosetting resins are considered due to their excellent comprehensive properties, but their economic efficiency, sustainability, and recycling need to be addressed urgently. Here, a recyclable cardanol biobased thermosetting resin was fabricated by epoxidizing biomass cardanol. Utilizing cationic polymerization to synthesize a cardanol glycidyl ether prepolymer (PCGE), which was cured with maleic anhydride (MAH). The effects of prepolymerization conditions on the structure and properties of PCGE were systematically explored. The cardanol-based resin was endowed with a gel content of 97.6% and a high glass transition temperature of 86 °C to exhibit competitive mechanical properties (43.4 MPa) and outstanding thermostability comparable to those of the commercial epoxy resin. Importantly, the fabricated resin could achieve rapid chemical degradability attributed to the dynamic ester bonds. Furthermore, the fabricated resin was compounded with carbon fiber (CF) to obtain CF/PCGE/MAH composites with high mechanical strength and admirable thermal resistance. This work provides a strategy for exploiting biobased resins and their CF composites, which benefits the efficient utilization and friendly production of biomass cardanol raw materials.