Synergistic Enhancement of Mechanical and Thermal Properties in Epoxy/Reduced Graphene Oxide/Multi‐Walled Carbon Nanotube Hybrid Nanocomposites

Incorporating hybrid fillers, such as reduced graphene oxide/multi‐walled carbon nanotube (RGO/CNT), into polymer matrices yields promising materials with enhanced mechanical, thermal, and dielectric properties, making them suitable for advanced engineering applications. In this work, reduced graphene oxide (RGO) was synthesized from natural graphite and subsequently used to prepare RGO/CNT hybrids via solution mixing with carboxyl‐functionalized multi‐walled carbon nanotubes (f‐CNT). Epoxy‐based nanocomposites with varying filler concentrations (0–1 phr) were prepared by incorporating RGO/CNT into the epoxy matrix, and the synergistic effects were evaluated through static and dynamic mechanical analyses. Compared with neat epoxy, the hybrid nanocomposites achieved remarkable improvements of 34%, 85%, and 130% in tensile, flexural, and impact strengths, respectively, even with the addition of only 0.25 phr RGO/CNT. Fracture toughness, determined by SEN‐TPB, increased by 179% with the addition of 0.5 phr RGO/CNT. Superior dynamic mechanical performance was also evidenced by increased storage modulus and elevated glass transition temperature. The simple and cost‐effective fabrication method can be extended to a wide range of polymeric systems, making this class of hybrid materials highly promising for advanced high‐performance applications in aerospace engineering, electronics, protective coatings, vibration‐damping systems, etc.