Research on microwave absorbing properties of polychloroprene matrices containing modified carbonyl iron powder

Preparation microwave absorbing composite films in different thickness. The composite films were made up of polychloroprene and carbonyl iron powder 94RC which was modified by vinyltrimethoxysilane. The experiments showed that, with thickness of 1.58mm and coating density of 3.30kg/m², the frequency width with reflectivity under -8dB reached 5. 2GHz of the whole frequency range. With the increase in the depth of the film, the absorption peak shifts to higher frequency and the absorption band becomes wider. According to resistance matching principle and electromagnetic spreading regulation, a three-layer film of transparent layer, transition absorption layer and significant magnetic absorption layer was designed. With thickness of 0.64mm and coating density of 0.71kg/m², the minimum reflectivity of the three-layer film was -13.45dB, and the frequency width with reflectivity under -8dB reached 5.51GHz of the whole frequency range.