Microwave reflectivity measurement of silicon urea polyvinyl alcohol / epoxy resin composites in X and Ku bands

In the paper presented here, a thermally stable epoxy resin modified urea - polyvinyl alcohol - silicon blends have been prepared by in situ polymerization technique. For this, the materials were modified with triethylene tetramine (hardener) to obtain highly cross-linked thermosetting resins. The authors have synthesized the polymer composites; silicon-urea-polyvinyl alcohol in three ratios in weight percentages with analytical reagent grade epoxy resin. The reflection characteristics of these polymer composites, made as thin slabs was carried out by a transmission/ reflection method using a vector network analyzer R&S ZVA40, in the X and Ku-bands [ 8.0 to 18.5 GHz ]. The microwave reflectivity properties of all three blends were evaluated, which is found to be remarkably high upto -48 dB at 13.3 GHz. A reflectivity of -10 dB or less could be obtained for over 6 GHz range in the entire tested range. The response slightly varies for all three ratios. After due comparison of their response, it is deemed to be suitable as microwave absorber in the X and Ku-bands. The morphological features of the composites were examined using x-ray powder diffratogram and scanning electron microscopy.