Effective attenuation of electromagnetic waves via silane surface modified zinc oxide/polybenzoxazine nanocomposites for EMI shielding application

Abstract

In recent years, there has been a significant emphasis on advancing nanomaterials with exceptional properties, including high reflection loss (RL), reduced thickness, broad bandwidth, and low density. The primary goal is to augment their effectiveness in absorbing EM waves while maintaining a streamlined manufacturing process. This study, investigated the application of novel thermosetting phenolic resin as a polymeric matrix for EM shielding. Among these resins options, benzoxazine stands out due to its exceptional characteristics, which encompass facile monomer preparation through solvent-free synthesis, the absence of by-product release during polymerization, high thermal stability and superb mechanical properties. The assessement of this resin both individually and in combination with zinc oxide nanoparticles. Silanization of the nanoparticles was confirmed via Fourier transform infrared spectroscopy (FTIR). The thermal properties were investigated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The outcomes indicated that the incorporation of zinc oxide nanoparticles enhanced the material's stability. The thermomechanical attributes of the composites were evaluated using Dynamic Mechanical Analysis (DMA), revealing an increase in the storage modulus and a decrease in the glass transition temperature (Tg). In summary, the results from the electromagnetic tests underscore the remarkable capability of the developed composites in absorbing EM radiation, achieving highly impressive RL values of up to –50 dB. However, they exhibited acceptable shielding efficiency.