Synthesis and microwave characterization of expanded graphite/novolac phenolic resin composite for microwave absorber applications

Ultra-Thin, Non-Metallic and Flexible Metamaterial Absorber for X-Band Applications: Design and Fabrication

“…Chemical oxidation and thermal treatment method is used to synthesize expanded graphite from natural graphite flakes [11]. For this, natural graphite flakes of size less than 2 μm are purchased from Mass Graphite and Carbon products, Mehsana, India and are used to prepare expanded graphite.…”

Electromagnetic properties and performance of exfoliated graphite (EG) – Thermoplastic polyurethane (TPU) nanocomposites at microwaves

“…In [15] the authors investigated the EM behavior at microwaves of graphene nanoplatelets (GNP) in natural rubber compounds at different GNP loadings (2-10 phr) between 1-12 GHz and they found a relatively weak impact of filler amount on most EM properties and EMI performance, probably due to the predominant presence of other fillers and additives of the rubber compound. In [16] EG (30, 40 e 50 wt.%) is disperse in novolac phenolic resin and, despite both real (e′ ) and imaginary (e′′) parts of permittivity are only scarcely influenced by the different amount of loading, an average absorbing performance of -14 dB is obtained in all cases, being the ratio e′′ e′ almost constant around the value of 1 [2]. To the best of our knowledge, EM performance of polyurethane matrix composites has been investigated only in systems containing CNT [17] or short CF (with silica) [18] as conductive fillers.…”

Synthesis of3,13‐diglycidyloxypropyloctaphenyldouble‐decker polyhedral oligomeric silsesquioxane and the thermal reaction properties with thermosetting phenol‐formaldehyde resin

“…Thermosetting phenol-formaldehyde (PF) resin is a general term resin with an excellent performance of good heat resistance, ablation resistance, and flame retardancy, and has been widely concerned since its commercialization. [1][2][3] Up to now, thermosetting PF resin has been widely used as thermal protection material and thermal conductivity material in hypersonic aircraft, missile, rocket and other defense technology objects of aviation and aerospace fields to protect their internal structure and equipment. [2,4] However, with the rapid development of aviation and aerospace technology in various countries around the world, PF resin, as an organic polymer, is still easily oxidized due to the phenolic hydroxyl group, methylol group and methylene group in the molecular structure, which affects the heat resistance, and no longer meet the requirements of thermal protection materials for hypersonic vehicles.…”

“…[1][2][3] Up to now, thermosetting PF resin has been widely used as thermal protection material and thermal conductivity material in hypersonic aircraft, missile, rocket and other defense technology objects of aviation and aerospace fields to protect their internal structure and equipment. [2,4] However, with the rapid development of aviation and aerospace technology in various countries around the world, PF resin, as an organic polymer, is still easily oxidized due to the phenolic hydroxyl group, methylol group and methylene group in the molecular structure, which affects the heat resistance, and no longer meet the requirements of thermal protection materials for hypersonic vehicles. [5][6][7] Therefore, the preparation of high-performance thermal protection materials had become one of the key technologies for the development of hypersonic vehicles, and the research on PF resin modification or the development of new highresidual carbon resins has also become hotspots in the field of protective materials.…”