Development of Flexible Hydrophobic Polypropylene/SPCB/GNP Hybrid Nanocomposite Films With Excellent EMI Shielding and Mechanical Properties

The demand for effective electromagnetic interference (EMI) shielding materials has driven the development of novel and facile approach for fabrication of conductive polymer nanocomposites. In this study, a polypropylene (PP)-based hybrid nanocomposite was prepared by incorporating Super P conductive carbon black (SPCB) and graphene nanoplatelets (GNP) via latex technology. A simplistic method of fabrication was adopted where the nanofillers were stirred into the PP latex at room temperature, ensuring the proper dispersion of fillers within the matrix. Hybridizing the nanocomposite by the usage of two different fillers has resulted in a substantial improvement in EMI shielding performance of the material along with its mechanical and thermal properties. The samples were fabricated and tested in three different thicknesses to ensure that EMI shielding effectiveness (EMI SE) is a thickness dependent property and also the studies were carried out over a broad range of microwave frequency. A high electrical conductivity of 7.6 S m-1 was obtained and exceptional EMI SE of 65 dB (X band), 69.76 dB (Ku band), and 72.38 dB (K band) was showcased by 2 mm thickness composites. The optical images of PP latex incorporated with the fillers gave a clear understanding about the formation of conducting networks within the polymer matrix at percolation threshold. The addition of SPCB and GNP also showed a significant increase in hardness and tensile strength of the composite and helped in protecting the polymer matrix against photo radiation. The fillers also aided in the enhancement of the hydrophobicity of the films. The thermal stability, crystallization temperature (TC) and melting temperature (TM) of the composites were also improved when compared to that of neat The works aims at fabricating a hydrophobic and low-density polymer nanocomposite showing excellent absorption dominant EMI SE.