Reinforcement of Epoxy Resin-Polyimide Composites Using Magnetic-Carbon Nanofiber and Titanium Dioxide as Hybrid Filler for Electromagnetic Interference Shielding Material

Polymer nanocomposites with hybrid fillers have been used as alternative materials for electromagnetic interference (EMI) shielding applications. The combination of magnetic-carbon nanofiber (Mag-CNF) and titanium dioxide (TiO₂) produces a unique hybrid filler which can improve the physical and mechanical properties of polymer materials. This research focuses on evaluating the effects of adding aminated Mag-CNF-TiO₂ as a hybrid filler in epoxy resin-polyimide composites. Amination was performed by reacting Mag-CNF and TiO₂ with ethylenediamine (C₂H₈N₂), sodium nitrite (NaNO₂), and sulfuric acid (H₂SO₄). The aminated hybrid filler was then used to reinforce epoxy resin and polyimide composites. The macroscopic appearance of the composites shows increased homogeneity or uniformity. The successful amination was analyzed using Fourier transform infrared (FTIR) spectroscopy, revealing the presence of the amine functional group as indicated by the amine absorption at 3773 cm^-1 (N-H) and 1336 cm^-1 (C-N). Then, the covalent reinforcement of epoxy resin-polyimide composite with aminated Mag-CNF-TiO₂ hybrid filler was assessed based on thermal properties, mechanical properties (tensile strength and hardness), and electromagnetic interference radiation. The thermal gravimetric analysis (TGA) profiles showed degradation of the composite because the chemical bonds between the polyimide and epoxy resin have broken. Owing to the stronger covalent crosslinks between the polymer and the filler, composites with amine-modified fillers exhibit higher mechanical properties than those without reinforcement. Furthermore, the epoxy resin-polyimide composite reinforced by aminated Mag-CNF-TiO₂ also demonstrated improved electromagnetic shielding ability. (author)