Multifunctional Epoxy Composites Reinforced With Hybrid <scp>MWCNT</scp> /Graphene‐Related Materials Buckypaper

ABSTRACT This study investigates the development of multifunctional epoxy composites reinforced with hybrid buckypapers composed of multi‐walled carbon nanotubes (MWCNTs) and graphene‐related materials (GRMs), including nanographite (NG) and graphene nanoplatelets (GNP). Hybrid buckypapers with different MWCNT/GRM ratios (25/75, 50/50, and 75/25 wt%) were processed via vacuum filtration and subsequently integrated into epoxy matrices through vacuum infusion. The results demonstrate that the architecture and composition of the hybrid buckypapers strongly govern the electrical, thermal, viscoelastic, and electromagnetic performance of the resulting composites. A synergistic interaction between one‐dimensional MWCNTs and two‐dimensional GNP promoted the formation of interconnected conductive pathways, enhancing charge transport and electromagnetic attenuation. The formulation containing 25 wt% MWCNT and 75 wt% GNP exhibited the best multifunctional performance, achieving electrical conductivity in the order of 10 −5 S m −1 and electromagnetic shielding effectiveness up to 40 dB. Thermogravimetric analysis (TGA) revealed increased thermal stability and carbon residue, while dynamic mechanical analysis (DMA) showed that the viscoelastic response depends on the balance between nanocarbon network continuity and resin infiltration. Microstructural observations confirmed efficient resin impregnation and strong interfacial interactions, which directly influenced the multifunctional response. Overall, the results demonstrate that hybrid MWCNT/GRM buckypapers act as tunable interlayers with multiple functionalities, enabling controlled optimization of electrical conductivity, electromagnetic shielding, and mechanical performance in epoxy composites, with strong potential for lightweight structural and electromagnetic management applications.