Superior high-temperature mechanical and thermal performance of carbon fiber/epoxy composites by incorporating highly dispersed aramid nanofibers

Enhancing the high-temperature properties of polymer-matrix fiber-reinforced composites is a challenging task, given the thermal limitations of polymer resins. In this study, we propose a straightforward and efficient method for producing high-performance carbon fiber/epoxy composites with superior high-temperature properties by incorporating highly dispersed aramid nanofibers. To achieve high dispersion of aramid nanofibers in the epoxy, we used a sequential solvent exchange method, which allowed us to fabricate B-stage cured resin films. The aramid nanofiber-hybridized carbon fiber composite, manufactured using resin film infiltration, demonstrated impressive mechanical and thermal properties. Specifically, in the glass transition temperature range at high temperatures, the composite provided 3.1, 5.1, and 6.8 times higher Young`s modulus, tensile strength, and short beam strength, respectively, compared to the unmodified composite. Moreover, incorporating aramid nanofibers significantly increased the glass transition temperature by 31 °C, resulting in 2.4 times higher storage modulus and improved thermal stability with an increase in the total weight residue at 800 °C by 33.7 %. Therefore, the highly dispersed aramid nanofiber-embedded carbon fiber composite shows great potential for use in high-performance polymer composite applications.