Effects of aramid nanofibers on the mechanical properties of epoxy resin and improved adhesion with aramid fiber

Abstract Inspired by the application of nano‐fillers in composite materials, well‐dispersed aramid nanofibers (ANFs) were prepared and added into the epoxy resin (EP) to improve the toughness and tenacity properties of the ANF/EP composites. The composites were characterized by mechanical property test, surface analysis, thermodynamic property analysis, and contact angle. Results showed that when the EP was added with 0.15 wt% ANF, the tensile strength, bending strength, and impact strength are increased by 28.2%, 81.9%, and 81.8% compared with pure EP, respectively. The thermal stability and infiltration of the composites are improved. The interlaminar shear strength and interfacial shear strength of the aramid fiber were increased by 53.1% and 92.7% compared with the not reinforced EP, demonstrating that the epoxy reinforced with ANF is also beneficial for improving the interfacial bonding strength of aramid fiber and EP. The mechanism of the epoxy reinforcement by ANF and the interface enhancements showed that the ANF could cause several crack bridges and strong hydrogen bond interaction interface.