Development of Multifunctional Polymeric Composites With Electromagnetic Properties for <scp>5G</scp> Technology Applications

ABSTRACT The growing demand for lightweight, flexible, and efficient materials for electromagnetic interference (EMI) shielding has driven the development of conductive polymer composites (CPCs) as sustainable and reliable alternatives. These materials are essential for protecting communication systems, electronic components, and ensuring the efficient operation of expanding 5G networks. This study presents the development and characterization of PLA/MWCNT and TPU/MWCNT composites, fabricated by melt mixing and compression molding with different loadings of multi‐walled carbon nanotubes (MWCNTs). Rheological analyses indicated that the dispersion of MWCNTs begins at around 3%, with a more pronounced effect in PLA. In particular, PLA/MWCNT composites with 12% filler, where the nanotubes are effectively dispersed, exhibited electrical conductivity on the order of 10 −3 S/cm. On the other hand, although TPU/MWCNT composites also showed an increase in conductivity with the addition of MWCNT, they did not reach the same order of magnitude (10 −3 S/cm), even at 12% filler content. This result may be associated with a less efficient dispersion of MWCNT within the TPU matrix. Electromagnetic shielding effectiveness (EMI SE) increased with MWCNT content, exceeding 60 dB in PLA and reaching up to 50 dB in TPU. Anechoic chamber tests with a 3D‐printed PLA/MWCNT (12%) box confirmed attenuations above 40 dB at 5.9 GHz and between 10 and 15 dB at 3.5 GHz, SEM analyses confirmed the rheological and electrical results, indicating a more homogeneous dispersion of nanotubes in the PLA/MWCNT composites than in the TPU/MWCNT ones. The results highlight PLA/MWCNT as a promising material for EMI shielding in electronics, 5G networks, and aerospace applications.