Effect of Silane Coupling Agent on the Properties of Recycled Carbon Fibers Reinforced Bio-based Epoxy Composites

In this work, the effect of a silane coupling agent on the mechanical behavior of recycled carbon fiber reinforced bio-based epoxy composites was studied. For this purpose, the surface of the recycled carbon fiber was treated with 3-aminopropyltriethoxysilane (APS) agent at the concentrations in the 0–8 wt.% range. Dynamic mechanical analysis and characterization of the tensile and flexural properties were performed to observe the mechanical behavior of the specimens, and the morphology of the fracture surface after mechanical testing was also studied by scanning electron microscopy. It was found that the glass transition temperature and the tensile and flexural strengths of the composites increased with an addition of a suitable amount of the silane agent (< 4 wt.%), which was attributed to the cross-linking and curing reaction between the amino groups of APS and the epoxy matrix that improved the interfacial bonding. Thus, an appropriate concentration of the silane coupling agent can improve the mechanical properties of recycled carbon fiber reinforced bio-based epoxy composites.