Electromagnetic shielding effectiveness of surface modified porous watermelon rinds biochar nutmeg short fibre reinforced lightweight vinyl ester biocomposite

Abstract

The present research aims to develop an Electromagnetic interference (EMI) shielding which is light weight by natural fiber, and filler reinforced polymer composite. The novelty of this study producing composite using waste biomass by treating the fiber and filler surface modification. As well as analysing the mechanical, dielectric, and EMI shielding efficiency of the composite in accordance to the ASTM (American Society for Testing and Materials) standard. The study founded that composite VNB2, with 2.0 vol.% biochar and 30 vol.% silane-treated nutmeg shell fiber, demonstrates the best mechanical performance, with a tensile strength of 154 MPa, tensile modulus of 5.6 GPa, flexural strength of 221 MPa, flexural modulus of 6.1 GPa, and it is 175%, 229.4%, 151.1%, 177.3%, respectively. However, the impact strength and hardness properties are improved with increase filler content of 4 vol.% of biochar and 30 vol.% silane-treated nutmeg shell fiber on composite VNB3, that is 5.8 J, and 90 shore-d and it is 383.3%and 9.8% increase when compared plain vinyl ester composite V, respectively, suggests that the combination of fiber and biochar provides excellent toughness. Similarly, the dielectric constant of VNB3 reaches 6.62, 5.57, 4.41, and 3.89 at E, F, I, and J, respectively, which it is 97.02%, 104.02%, 99.54%, 131.54%, respectively, due to the formation of conductive networks and improved interfacial polarization. Additionally, the highest EMI shielding effectiveness is observed in VNB3, reaching 8.82, 14.28, 20.16, and 29.82 dB at E, F, I, and J, respectively and it is 299.09% 61.90%, 52.38% 50.22%, respectively, indicating that the increased biochar content enhances charge transport and multiple reflections, optimizing wave attenuation. Owing to such features it could be applied in most of electric and electronic equipment used industries like space craft, communication, navigation, medical, automobile, and information technology, etc.