Influence of Epoxy Resin Treatment on the Mechanical and Tribological Properties of Hemp-Fiber-Reinforced Plant-Derived Polyamide 1010 Biomass Composites

In this study, we investigated the influence of epoxy resin treatment on the mechanical and tribological properties of hemp fiber (HF)-reinforced plant-derived polyamide 1010 (PA1010) biomass composites. HFs were surface-treated using four types of surface treatment methods: (a) alkaline treatment using sodium chlorite (NaClO(2)) solution, (b) surface treatment using epoxy resin (EP) solution after NaClO(2) alkaline treatment, (c) surface treatment using an ureidosilane coupling agent after NaClO(2) alkaline treatment (NaClO(2) + A-1160), and (d) surface treatment using epoxy resin solution after the (c) surface treatment (NaClO(2) + A-1160 + EP). The HF/PA1010 biomass composites were extruded using a twin-screw extruder and injection-molded. Their mechanical properties, such as tensile, bending, and dynamic mechanical properties, and tribological properties were evaluated by the ring-on-plate-type sliding wear test. The strength, modulus, specific wear rate, and limiting pv value of HF/PA1010 biomass composites improved with surface treatment using epoxy resin (NaClO(2) + A-1160 + EP). In particular, the bending modulus of NaClO(2) + A-1160 + EP improved by 48% more than that of NaClO(2), and the specific wear rate of NaClO(2) + A-1160 + EP was one-third that of NaClO(2). This may be attributed to the change in the internal microstructure of the composites, such as the interfacial interaction between HF and PA1010 and fiber dispersion. As a result, the mode of friction and wear mechanism of these biomass composites also changed.