Construction of in-situ grid conductor skeleton and magnet core in biodegradable poly (butyleneadipate-co-terephthalate) for efficient electromagnetic interference shielding and low reflection

Abstract

Conductive polymer composites have become an emerging electromagnetic interference (EMI) shielding material due to the advantages of light weight, corrosion resistance and low cost. However, low shielding efficiency, high reflectivity and non-biodegradability limit their applications in high-power devices, precision instruments and environmentally friendly fields. In this paper, poly (butyleneadipate-co-terephthalate) (PBAT) based EMI shielding composites with three-dimensional hybrid conductive networks as well as magnetic nanoparticles were prepared through the layer by layer coating and hot pressing. Regular PBAT microspheres were synthesized for the first time and used for isolated structure design. The interfacial junctions of the isolation units are composed of in situ synthesized polyaniline (PANI), as well as transition metal carbide (MXene) and CNTs that were adhered by PANI. The synergistic combination of these three conductive fillers promotes the construction of efficient shielding networks. The distribution of Fe3O4@MWCNT nanoparticles inside the PBAT matrix reduces the reflection of EM waves and weakens the EM radiation energy through magnetic loss. The shielding efficiency of the composites is up to 70.1 dB, and the percentage of reflected EM waves is as low as 26%. These biodegradable polymer-based EMI shielding composites with satisfactory shielding efficiency and low reflection function are expected to be widely used in the next generation of smart and environment-friendly electronic devices.