Biopolymer-coated composites for enhanced dielectric and electromagnetic interference shielding applications - a green initiative

The utilization of natural fibre-reinforced polymer composites has been tremendously growing in various applications of automotive and aerospace components. In this aspect, the researcher’s community is approaching the global market with new ideas for developing a complete eco-friendly, sustainable, and green composite. Plant-based composites have received great interest from the initial stage due to their unique features, such as lightweight, corrosion resistance, specific properties, excellent mechanical and thermal properties. This research article attempts a novel technique of coating the fibres with polylactic acid (PLA) as a part of surface modification which improves fibre properties. Then the fibres were reinforced with various weight percentages of conductive fillers, such as Copper (Cu), Alumina (Al 2 O 3 ), and Graphene (Gr), to improve the electrical properties using the hand layup technique. Then the fabricated samples were tested for dielectric and electromagnetic interference (EMI) shielding effectiveness (SE) using resonance and open shielded method. Based on the test results, it was noted that the dielectric strength (K) and shielding effectiveness (SE) of the composites started to increase with the increase of weight percentage of conductive fillers, which highlighted that by incorporating conductive fillers, the fibres started losing their insulation properties. The composites with 0.9 wt% of nanofillers achieved maximum SE abs of −19.61 dB and a SE total of −22.67 dB at a frequency range of 8–12 GHz.