Electromagnetic evaluation of radar absorbing materials based on conducting polypyrrole and<scp>organic–inorganic</scp>nanocomposite of polypyrrole/kaolinite
Caroline P. R. Malere, Bruno Ferraz Donati, Nicholas Eras Fonseca, Valdirene Aparecida da Silva, Liliane Maria Ferrareso Lona
Abstract
Abstract This paper presents a study of radar absorbing materials (RAM), based on conducting polymer polypyrrole (PPy) and organic–inorganic nanocomposite of PPy filled with lamellar structure kaolinite clay (PPy/Kao) for X‐band frequency range application. PPy was obtained via a chemical synthesis using doping agent chloride acid, lauric acid, and sodium dodecyl sulfate. The nanocomposites were produced via in situ polymerization, where the same experimental conditions were applied for PPy synthesis. The radar absorbing composite was obtained by mechanically mixing an epoxy resin matrix with the synthesized materials. The characterization was done using infrared spectroscopy, scanning electron microscopy (SEM), thermogravimetric analyses, and differential scanning calorimetry thermal analysis, and electromagnetic measurements. Kao in the nanocomposite was used to promote polymer anchoring, behaving as a host agent. SEM demonstrated that the synthesized nanocomposites produced growth morphology of interconnected nanoparticles in an almost spherical shape and mostly globular in a cauliflower shape, with homogeneous sizes and packaged structure. Results showed that the RAM obtained presented a good performance as an electromagnetic wave absorber, with thermal stability above 120°C and incident wave attenuation ranging from −10 to −33 dB (90%–99.9%) in the X‐band.