Enhanced Microwave Absorption and Mechanical Properties of PLA/PP/PMMA Composites Reinforced With MWCNTs: Toward Efficient Electromagnetic Pollution Mitigation

High‐performance microwave‐absorbing composites are crucial for addressing electromagnetic pollution. Multi‐walled carbon nanotubes (MWCNTs) function as both microwave absorbents and reinforcing agents in composites. These are integrated with polylactic acid (PLA), polypropylene (PP), and polymethyl methacrylate (PMMA) using twin‐screw extrusion and fused deposition modeling (FDM) to produce PLA/PP/PMMA/MWCNTs composite wires designed for microwave absorption. Notably, the MWCNTs‐2.5 sample demonstrates a minimum reflection loss of −47.62 dB at 3.1 mm and a maximum effective absorption bandwidth of 1.82 GHz at 2.6 mm, covering 14.88 to 16.70 GHz, which is further supported by radar cross‐sectional (RCS) simulation showing its superior electromagnetic energy attenuation. Additionally, the MWCNTs‐2.5 sample exhibits enhanced strength and toughness, with a tensile strength of 19.86 MPa, marking a 13.9% increase compared to the control sample without MWCNTs. The elongation at break has improved from 21% to 27.2%. This research introduces an innovative composite material that efficiently mitigates electromagnetic pollution and boasts superior mechanical properties, offering new possibilities for the advancement of organic–inorganic composite microwave‐absorbing material preparation technology.