Synergistic Conductivity and Electromagnetic Interference Shielding Effectiveness of Epoxy/Carbon Fiber and Epoxy/Carbon Black Composites via Mixing with Bamboo Charcoal

Abstract

This study was aimed at preparing electromagnetic interference (EMI) shielding materials based on carbon black (CB), carbon fiber (CF), bamboo charcoal (BC), and epoxy resin. The effects of adding bamboo charcoal on the mechanical properties and electrical resistivity of epoxy composites were studied. Scanning electron microscopic (SEM) analysis, electrical resistivity, and electromagnetic interference (EMI) shielding effectiveness were also investigated. The composites were prepared at 120 °C by the curing-molding method through blending the fillers in epoxy resin. The results revealed that the BC/CB and BC/CF composites had perfect conductive network structure and resulted in better dynamic thermal mechanical properties. The electrical resistivity declined with the increase of bamboo charcoal contents; consequently, the EMI shielding effectiveness improved gradually. The lowest electrical resistivity, down to 0.071 Ω·m, corresponded to the best EMI shielding effectiveness of BC/CF composites, which could be above 60 dB over a frequency range of 30 MHz to 1500 MHz while the carbon fiber content was at 40 wt.%.

Recent advances in electromagnetic interference shielding properties of carbon-fibre-reinforced polymer composites—a topical review

“…This is ascribed to the less favourable aspect ratio of carbon particles, which limits their ability to bridge the gaps between carbon fibres [149]. Similar trends were noted [137,175]. With the aim of improving electrical properties, metal particles were added to fibre polymer composites in the work of Li et al [176].…”

“…One of the ways to reduce manufacturing costs is to partly replace carbon fibres with black carbon particles. This approach was undertaken by Das et al and [137], Wen et al [175] and Pramanik et al [149]. For a fixed total filler content of 60 phr, the SE was found to decrease with an increasing proportion of carbon black particles, from a maximum of 55 dB for 10phr to just 23 dB for 50 phr.…”

Electromagnetic Characterization of Psu/Carbon Black Multifunctional Composites

“…The multifunctional composite class seeks to join structural functions of composites such as strength, stiffness, fracture toughness and damping to non-structural functions, such as electromagnetic shielding [6]. By joining a high-performance engineering polymer such as polysulfone, which, among other properties, has high hardness, impact strength and high temperature resistance, [7] with the carbon black load, a material widely used in electromagnetic shielding research [8][9][10][11], multifunctional composites with great potential may be obtained.…”