Hybrid carbonaceous materials for radar absorbing poly(vinylidene fluoride) composites with multilayered structures
Tamara Indrusiak, Iaci Miranda Pereira, Ketly Pontes, Elaine C. Lopes Pereira, G.G. Peixoto, Antônio C.C. Migliano, Bluma G. Soares
Abstract
Abstract Poly(vinylidene fluoride) (PVDF) based composites loaded with 3 wt% of carbon black (CB), graphite (GF), and the hybrid CB/GF (1.5/1.5 wt%) were prepared by melt mixing and tested as microwave absorbing material at X‐band frequencies (8–12 GHz). The materials were processed and pressed at 220°C into plates of 20 × 20 × 0.1 cm 3 . Dielectric and magnetic properties were evaluated using the wave‐guide accessory to simulate the reflectivity of single‐layered PVDF composites through impedance matching behavior. The best absorbing properties were achieved with the composite loaded with the CB/GF hybrid material, whose maximum of radiation attenuation of −33 dB at 9.3 GHz was predicted with 4 mm thickness. Afterwards, the reflectivity of sandwiched structures (20 × 20 cm 2 in size) with one‐layer honeycomb core sandwiched by two plates of PVDF composites was measured. The PVDF/HB‐honeycomb‐PVDF/HB structure reached reflection loss = −12 dB ( E a = 94% ) on a broadband frequency. CB/GF hybrid material in PVDF composites has a promising future as a lightweight and cost‐effective microwave absorbing materials for both telecommunication and stealth technology.