The Effect of SiO₂ Nanoparticle on the Mechanical Properties of Silica-Epoxy Nanocomposites-An Experimental Study

Polymer nanocomposites, featuring reinforcing particles smaller than 100 nm, exhibit superior mechanical properties compared to conventional composites. This study investigates the effect of nanoparticle size and weight fraction on the Young’s modulus and tensile strength of epoxy-silica nanocomposites. To evaluate their mechanical behavior, epoxy-silica samples were prepared using nanoparticles sized 15 nm, 20 nm, and 80 nm at 3% and 5% weight fractions. Ultimate stress, yield stress (0.2%), maximum strain, and Young’s modulus were measured. Results showed that adding silica nanoparticles enhanced the ultimate tensile stress, yield stress, and Young’s modulus of pure epoxy. Notably, nanocomposites with 80 nm particles at 3% loading displayed the highest strain. At 5% loading, 20 nm nanoparticles exhibited the highest tensile strength and stiffness among the tested samples, while 15 nm particles showed comparatively lower improvements, likely due to increased agglomeration. Additionally, a general trend of increased stiffness was observed with smaller particle sizes, although deviations occurred due to dispersion and porosity effects.