Flame Retardant Multilayer Microwave Absorbers Based on Powdered Activated Charcoal

Abstract

The article presents the technology for obtaining flame retardant microwave absorbers based on powdered charcoal. These absorbers include three layers. The outer layer of these absorbers is formed based on a mixture of powdered aluminum oxide or titanium dioxide and a flame retardant paint, the intermediate layer is based on a mixture of powdered activated charcoal impregnated with a calcium or magnesium chloride aqueous solution, and a gypsum aqueous solution, and the inner layer is based on aluminum-containing foiled polymer film. The results of an experimental test of the presented technology are provided. They include the results of a study of the process of interaction of an open flame with absorbers manufactured in accordance with the presented technology, the results of a study of the process of interaction of IR radiation with such absorbers, as well as the results of a study of the electromagnetic radiation absorption characteristics in the frequency range 2.0–17.0 GHz of such absorbers. Using the first of the indicated results, it was confirmed that absorbers manufactured in accordance with the presented technology are flame retardant. Using the second of the indicated results, it was confirmed that absorbers manufactured in accordance with the presented technology provide an effective reduction in the energy of IR radiation. Using the third of the indicated results, patterns of changes in the absorption characteristics of electromagnetic radiation in the frequency range 2.0–17.0 GHz of absorbers manufactured in accordance with the presented technology were established, depending on the composition of their outer and intermediate layers.