Li Y, Luo Z, Yang L, et al
Polymer, 2019: 121550
The interfacial properties of aramid fibres (AFs) affect their mechanical behaviours. In this work, polyamide acid (PAA) was grafted onto the surface of aramid fibres (AF@PAA) to reinforce epoxy resin (EP E44) by improving the interfacial properties. The AF@PAA contained many active groups and improved the roughness of aramid fibres on the surface, which improved the interfacial performance and mechanical properties of AF-reinforced E44 composites. FTIR and XPS showed the introduction of C–O and –COO–, which confirmed the existence of chemical reactions among groups between the aramid fibres and polyamide acid. A micro-droplet test proved that the benzene ring of the AF could be oxidized under high temperature, and the oxygen-containing groups generated during the oxidation process were important for the grafting process of polyamide acid. The interfacial shear strength (IFSS) increased by 40.7% after treatment with 5 wt% polyamide acid. This study provides a feasible method for interfacial modification in AF-reinforced epoxy resin composites and may be applicable to rubber composite systems.
