Investigation of the microwave absorbing properties on polymer sheets

Electromagnetic (EM) absorbers are becoming an important tool in the recent advanced technologies as well as for environments to minimize the level of microwave radiations in specific structures or places. Indeed, they are employed in radar absorbing materials (RAMs) and in defense, communication electronics, medical equipment, human health care, laboratory environments and public safety issues. In strategic areas, where the electromagnetic interference (EMI) shielding effectiveness is essential, the components and parts made by EMI shielding materials is to be upgraded. The EM shield play a significant role in reducing the intensity of reflected and transmitted EM waves. Recently, research on EM wave absorbers is focused on polymer-based structures, and layered carbon structures. The basic qualities of polymer and carbon have been successfully applied to minimize the reflection coefficient, and maximize absorption coefficient in metrology as well as in defense equipment’s. In this context, most of the studies use composites made with polymers and carbon materials and some studies are focused on foamed structures and metamaterials. In the present work, polyaniline (PANI) and carbon fiber (CF)-based paper like sheet structures were produced by compression molding technique and their electrical and EMI shielding properties are measured in X-band (8.2–12.4 GHz) frequency range. PANI paper has been found to have an electrical conductivity of 12.48 S/cm and EMI shielding effectiveness of PANI paper is found to be − 26.82 dB at a thickness of 0.75 mm. Scanning electron microscopy (SEM) approves the coating of polymer on carbon fiber and thermogravimetric analysis (TGA) demonstrates that the presence of carbon fiber drastically improves the thermal stability of the polymer sheets .