Tailoring the Performance of Nano Silica Reinforced PA ‐6,6 Nanocomposite: Insight Into Their Structural, Thermo‐Mechanical, Tribological, and Scratch Resistance Behavior

ABSTRACT This study explores the structural, thermal, mechanical, tribological, and scratch resistance behavior of the silicon dioxide (SiO ₂ ) nanoparticles reinforced with polyamide‐6,6 (PA‐6,6). Composites were fabricated through the melt‐mixing and injection molding techniques, with varying SiO ₂ concentrations. Thermogravimetric analysis confirmed improved thermal stability of the nanocomposites relative to pristine PA‐6,6. Mechanical testing revealed that 3–5 wt.% is the optimum reinforcement of SiO ₂ filler contents. Tensile strength increased by 24.6% at 3 wt.% of SiO ₂ , while 5 wt.% conferred nearly 19% higher flexural strength compared to the unfilled PA‐6,6. Tribological performance was evaluated under varying normal loads and frequencies. At 3 wt.% SiO ₂ and a frequency of 5 Hz, the coefficient of friction decreased by approximately 6% and 8% at 10 and 30 N, respectively, while at 25 Hz, further reductions of roughly 29% and 22% were observed at 30 and 50 N loads. Specific wear rate declined as SiO ₂ content increased, with optimal values at 3 wt.% for 5 Hz and 5 wt.% for 25 Hz, accompanied by smoother worn surfaces, and diminished surface damage. Additionally, incorporating SiO ₂ nanoparticles resulted in an increase in the scratch hardness characteristics, demonstrating enhanced mechanical integrity compared to the pure PA‐6,6 matrix.