Impact of Montmorillonite Nanoclay on the Performance of Alkali-treated Agave/Epoxy Biocomposites

This study investigates the influence of montmorillonite nanoclay (MMT) filler on the mechanical and structural performance of alkali-treated Agave sisalana fiber-reinforced epoxy composites. Six composite formulations (AM1–AM6) were fabricated with constant epoxy content (60 wt.%) and varying fiber and nanoclay percentages. Composites AM1 to AM5 incorporated MMT filler (1.5–7.5 wt.%) along with agave fiber (32.5–38.5 wt.%), while AM6 served as the control sample without nanoclay. Mechanical tests, including tensile, flexural, impact, and Shore D hardness measurements, were conducted. Water absorption characteristics and morphological analysis using scanning electron microscopy (SEM) were also evaluated. The AM4 composite (3 wt.% MMT, 37 wt.% fiber) exhibited the highest tensile strength (68.4 MPa), flexural strength (110.1 MPa), hardness (88.7 Shore D), and impact strength (36.8 J), along with the lowest water uptake (10%). SEM micrographs confirmed superior fiber–matrix adhesion and uniform nanoclay dispersion at the optimal filler loading. Excessive nanoclay loading (AM1, 7.5 wt.%) caused particle agglomeration, leading to performance deterioration. Overall, 3 wt.% MMT was identified as the optimum filler concentration, highlighting the synergistic role of nanoclay and treated natural fibers in enhancing epoxy composite performance.