A self-healing and flexible Ag@carbon fiber/polyurethane composite based on disulfide bonds and application in electromagnetic interference shielding

Abstract

With the wide application of electronic equipment, the demand for the efficient performance of electromagnetic interference (EMI) shielding materials has become increasingly urgent to meet different requirements and electromagnetic environments. In this study, a flexible composite with both self-healing and reliable EMI shielding functions was facilely developed. Firstly, we synthesize Ag@Carbon fiber (CF) by electroless plating method, and we can see that the silver layer wrapped CF completely by scanning electron microscope (SEM). Then we synthesize polyurethane (PU) with disulfide, and mix Ag@CF with PU mechanically to prepare Ag@CF/PU composite. Ag@CF/PU achieved satisfactory mechanical properties, EMI shielding performance and self-healing performance. When the filler content was 3 wt%, the tensile strength of composite was 1.63 MPa, the highest EMI shielding effectiveness (SE) was 10.3 dB at X-band, and self-healing efficiency of tensile strength was 96%. With the increase of filler content, the tensile strength and EMI SE of composite improved, and self-healing efficiency decrease. When the filler content was 20 wt%, the tensile strength was 7.95 MPa, the highest EMI SE was 26 dB and self-healing efficiency of tensile strength was 28%. This work demonstrated a self-healing flexible EMI shielding composite material that ensured reliability.