Investigation of mechanical properties and characterization of Luffa cylindrica and sisal fiber-reinforced epoxy hybrid composites: influencing of B4C

The author examines the mechanical properties of epoxy hybrid composites reinforced with boron carbide (B₄C) particle filler, Luffa cylindrica, and sisal fiber. The fibers from Luffa cylindrica and sisal were treated with 5% of NaOH solution. Composite laminates were created using the compression molding technique in various compositions such as 10–15 wt.% of Luffa cylindrica, 10–15 wt.% of sisal fiber, and 0–10 wt.% of B₄C particles with 70 wt.% of epoxy resin. As per the ASTM standards, the specimens from each composition were prepared to observe the mechanical properties such as ultimate tensile strength (UTS), flexural test, and impact test. The sample of 11.25 wt.% Luffa cylindrica/11.25 wt.% sisal fiber/7.5 wt.% B₄C particles significantly improved the UTS of 38.56 MPa and impact strength of 6 J, whereas 10 wt.% Luffa cylindrica/10 wt.% sisal fiber/10 wt.% B₄C particles had demonstrated notable improvements in flexural strength of 58.23 MPa. As a result, it is observed that the mechanical properties of the fabricated composites were markedly improved by the increment of B₄C particles. A scanning electron microscope was used to examine the morphological behavior of the fabricated composites, comprising void formation and the interfacial bond between the binder and fibers.