High strength epoxy nanocomposites reinforced by epoxy functionalized aramid nanofibers

Thermosetting polymers have been demonstrated to exhibit improved mechanical properties when nanofillers are introduced. These improvements can be further increased through the introduction of covalent linkages between the polymer matrix and nanofillers that enhances the chemical interaction. Here, aramid nanofibers (ANFs) are functionalized using a glycidyl ether silane coupling agent and their effect on the mechanical properties of epoxy are investigated. The results show that Young's modulus and tensile strength of 1 wt % epoxy functionalized ANFs (EANFs) reinforced nanocomposites increase by 16.8% and 14.0%, respectively, and fracture toughness increases by 4.4 times with the addition of 1.5 wt % EANFs. Additionally, both an increase in storage modulus and glass transition temperature are observed during dynamic mechanical analysis with increasing percentage of EANFs. Thus, this work demonstrates that the EANFs can further enhance the mechanical properties of epoxy nanocomposites through chemical crosslinking between the epoxy matrix and ANFs.