Surface-modified carbon fiber for enhanced electromagnetic interference shielding performance in thermoplastic polyurethane composites

Abstract

There has been a growing interest in developing carbon-based polymer composites for electromagnetic interference (EMI) shielding materials. To achieve a high EMI shielding performance, the morphology of fillers in composites must be controlled. Although carbon fibers (CFs) have remarkable thermal and electrical properties and low density, their poor dispersion behavior within polymer matrix limits their practical applications as EMI shielding materials. In this study, we report an efficient method to disperse CFs within a thermoplastic polyurethane (TPU) matrix using pyranine-functionalized polyether (Polyether–pyranine) as a dispersing agent. Polyether–pyranine was grafted on the CF surfaces through π-π interactions between the CF and pyranine groups to produce surface-modified CFs (SCFs). Compared to CFs, the SCFs exhibited an improved dispersion stability within a TPU polymer matrix. Furthermore, a TPU composite with SCFs achieved an enhanced electrical conductivity and EMI shielding performance, which was primarily ascribed to the increased structural connectivity between the SCFs due to excellent dispersion.

A review of high-performance carbon nanotube-based carbon fibers

“…However, CNTs have high surface energy and are very long, making them prone to aggregation. In fact, bundled CNTs can even degrade the properties of composites when mixed with other materials [100][101][102][103]. Therefore, the dispersibility of CNTs is crucial, and efforts to physically disperse bundles through sonication, homogenization, and sidewall modification are actively being made [104,105].…”

Electromagnetic absorption shielding effectiveness and physical‐mechanical properties of rubber composites

“…Different types of carbon-based fillers (mostly carbon nanotubes, carbon fibers, graphite, graphene, graphene oxides, or carbon black) as well as inorganic fillers (metal-based powders, metal oxides, and ferrites) in form of particles, fibers, ribbons, flakes, platelets, tubes, or sheets have been tested. [9][10][11][12][13][14][15][16][17][18][19][20][21] Each of the fillers can provide specific characteristics to the polymer matrices, not only from the point of shielding effectiveness but also with respect to their processability and properties of the final products. Carbon-based fillers are characterized by unique electrical conductivity, which is subsequently reflected in high electrical conductivity of polymer composites.…”

“…Recently, polymer composites filled with various fillers have been efficiently tested as potential materials for EMI shielding. Different types of carbon‐based fillers (mostly carbon nanotubes, carbon fibers, graphite, graphene, graphene oxides, or carbon black) as well as inorganic fillers (metal‐based powders, metal oxides, and ferrites) in form of particles, fibers, ribbons, flakes, platelets, tubes, or sheets have been tested 9–21 . Each of the fillers can provide specific characteristics to the polymer matrices, not only from the point of shielding effectiveness but also with respect to their processability and properties of the final products.…”