Microwave absorbing properties of carbonyl iron room temperature vulcanized silicone rubber composites

In order to prepare a high-bandwidth absorbing material with both mechanical properties and electromagnetic absorption properties, a nano-particle modification and physical blending method were used to design and prepare a carbonyl iron room temperature vulcanized silicone rubber composite material based on polydimethylsiloxane. The mechanical properties and wave absorbing properties of the composite material were systematically analyzed. The results show that when the mass fraction of white carbon black is 3%, the composite material has the best comprehensive mechanical properties and is convenient for material processing; the composite material is a magnetic loss type wave absorbing material, and the attenuation constant of the material is positively correlated with the carbonyl iron content and frequency. According to simulation calculations, the absorption peak of electromagnetic waves gradually shifts to low frequency as the thickness of the composite material and the content of carbonyl iron are increased at 2-18 GHz. When the thickness of the composite material is 1.5 mm and the mass fraction of carbonyl iron is 75%, the effective absorption bandwidth of the absorbing material can reach 9.07 GHz, accounting for 56.68% of the target bandwidth. In practical applications, the formula can be optimized and the thickness of the material can be controlled according to the needs of the application scenario to achieve the best absorbing effect.