A Pathway to Better EMI Shielding Performance in Natural Rubber Through Ternary Carbonaceous Filler Systems

In the present study, we fabricated and characterized ternary hybrid fillers of conductive carbon black (CCB), carbon nanotubes (CNT), and reduced graphene oxide (RGO) reinforced natural rubber (NR) composites. The ternary filler system exhibited good filler-polymer interaction as observed from the cure characteristics and mechanical properties. We used impedance analysis to study the dielectric permittivity and associated polarization mechanisms, and the AC conductivity was fitted using the Jonsher Power law. The presence of functional groups on the ternary nanofiller surfaces caused increased filler-filler interactions, leading to the formation of an excellent conductive network. Mechanical and viscoelastic studies revealed the reinforcing effect of the CCB, CNT, and RGO fillers. The theoretical models, such as Nicolais-Narkis and Turcsanyi, were employed to predict the tensile strength. Morphological analysis confirms the homogeneous dispersion of filler in the matrix. The present system also demonstrated excellent electromagnetic interference (EMI) shielding performance, with the highest shielding effectiveness (SE) values of 37.4 and 35.3 dB at 12 GHz for the ternary composites, satisfying commercial requirements.