Effect of aramid nanofibers on interfacial properties of high performance fiber reinforced composites

High performance fiber reinforced composites (HPFRC) have attracted considerable attention due to their high strength, high modulus and good designability. But the poor interface due to the smooth fiber surface and few active groups limits the application of the composites. Aramid nanofibers (ANFs) have been widely used as polymer framework in electrical and biological fields due to its large specific surface area and high mechanical properties. In this work, robust HPFRC was achieved via dip-coating approach of the fabrics. Instead of Kevlar fiber, Poly(p-phthaloyl-p-phenylenediamine) (PPTA) were served as precursor to prepare ANF solution. Aramid and carbon fabrics were then impregnated with ANF solution to study the effect of ANF on the interfacial properties of fiber reinforced composites. After modification, the roughness and polarity of the fiber were considerably improved. The inter-laminar shear strength (ILSS), mode I fracture toughness, GIC, and flexural properties of the composites were greatly enhanced, indicating that the study provides an effective method to achieve high strength HPFRC.