Electromagnetic interference shielding behavior of polypyrrole-impregnated poly(ether imide)/sulfonated poly(ether ether ketone) composites

Abstract

Electromagnetic interference (EMI) shielding materials are of major interest for modern society due to proliferation of electronic instruments and it reports the designing of electromagnetic radiations shielding material against electromagnetic pollution. Here, we prepared a series of composites comprising polyetherimide (PEI) with sulfonated poly(ether ether ketone) (SPEEK) by solvent casting method, having SPEEK loading ranging from 10 to 50 wt%. All the composites and PEI films were impregnated with pyrrole via in situ polymerization method to enhance their electrical conductivity. The morphology of composites was studied by SEM (scanning electron microscopy) and XRD (X-ray diffraction) analysis. Structural and thermal properties were investigated by Fourier-transform infrared spectroscopy (FT-IR), TGA and DSC, respectively. Electrical conductivity was analyzed by two probe method. Maximum conductivity of 2.24*10−4 S/cm was achieved at 50 wt% loading of SPEEK, due to the presence of conductive network between polypyrrole (PPy) and SPEEK throughout PEI matrix. These composites exhibited an average electromagnetic interference SET values up to −21 dB which makes them capable for shielding in the frequency range of 8.2–12.0 GHz (X-band). This study provides an avenue for fabrication of absorption dominating EMI shielding composites, which is promising material for commercial applications in next generation electronic instruments.