Synthesis and application of electromagnetic waves absorbers nanocomposites based on poly(aniline–co–melamine)/iron oxide nanoparticles in epoxy resin

Abstract Poly(aniline–co–melamine)/iron oxide (Fe 3 O 4 ) nanoparticles (PAMF) nanocomposites were synthesized and applied in the epoxy matrix (EP) as an absorber of electromagnetic waves. For this purpose, Fe 3 O 4 nanoparticles were synthesized via a chemical coprecipitation method as the core. Then aniline with melamine was in‐situ oxidative polymerized and formed the shell surrounding the Fe 3 O 4 nanoparticles. Fourier Transform Infrared Spectroscopy (FT‐IR), Thermogravimetric Analysis (TGA), X‐ray Diffraction (XRD), Vibrating Sample Magnetometry (VSM), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) analyses corroborated the successful synthesis of nanoparticles and the PAMF core‐shell nanocomposites. In the synthesis of nanocomposites, different ratios of composition were examined, and the optimum values of aniline/melamine (3:1 mol%), Fe 3 O 4 to poly(aniline‐co‐melamine) (PAM) (0.5 wt%) and PAM to EP resin (5 wt%) were obtained. Compared to PAM and EP, the electromagnetic wave absorption features of the PAMF nanocomposite significantly increase due to the magnetic and dielectric loss. Through reflection loss (RL) analysis, the capability to absorb electromagnetic waves of PAMF‐based epoxy was evaluated. Maximum RL at 10.2 GHz is −37.5 dB and at a thickness of 5 mm a broad electromagnetic absorption bandwidth (EAB) (RL < −20 dB) of 3.5 GHz (9–11.5 GHz) and a low filler content of 5 wt% was obtained for the magnetic nanocomposite. The results indicate that the magnetic nanocomposite could effectively absorb electromagnetic waves. Highlights Synthesized of core‐shell poly(aniline–co–melamine)/iron oxide nanocomposites. The magnetic nanocomposite has effectively absorbed electromagnetic waves. The optimum value in aniline/melamine (3:1) and composite to epoxy (5 wt%) Achieved good reflection loss in the low content of nanocomposite in epoxy. Electromagnetic shielding applications are achieved in high thickness.