Development of eco-friendly composite of carbon black (CB) with polyhydroxy butyrate–co-polylactic acid (PHB–co-PLA) for effective electromagnetic interference shielding

Recently, the rapid development of electronic science and technology has led to concerns about electromagnetic pollution, which poses significant risk to human health. However, traditional metal-based electromagnetic interference (EMI) shielding materials are heavy and have poor chemical resistance. Therefore, there is an urgent need to develop lightweight composites that exhibit excellent chemical resistance. Although plastic is generally used in such composite materials, it has contributed to environmental pollution. Therefore, to address the two problems of environmental and electromagnetic pollution, the present study examines the use of the green polymer, polyhydroxy butyrate–co-polylactic acid (PHB–co-PLA), along with carbon black (CB), to prepare composite materials via a simple hot-pressing method. The miscibility of the composite is confirmed via XRD, FT-IR, and SEM analysis. Moreover, the as-fabricated composite materials exhibit improved mechanical properties, electrical conductivity, and EMI shielding effects (SEs) compared to those of the pure PHB–co-PLA. In particular, the composite with 15 wt.% CB exhibits an EMI SE of up to 25.31 dB, thereby shielding 99.70% of the electromagnetic energy. The outstanding performance of these composites gives them tremendous potential for various applications in mitigating electromagnetic interference issues.

Graphical abstract

This study presents a sustainable and lightweight composite based on PHB-co-PLA and carbon black (CB), fabricated via a simple hot-pressing process, as an effective alternative to conventional metal-based EMI shielding materials. The composite demonstrates improved electrical conductivity and EMI shielding effectiveness (up to 25.31 dB at 15 wt% CB), attributed to the conductive network formation and enhanced interfacial compatibility. This environmentally friendly approach offers a practical solution to mitigate both electromagnetic and plastic pollution.