Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE This study employs a twin-screw to prepare a 3D printing wire composed of PLA/PP/PMMA/MWCNTs. With 2.5% MWCNTs, the composite wire delivers outstanding microwave absorption efficiency (−47.8 dB RLmin, 1.82 GHz EAB) and enhanced mechanical performance (19.86 MPa tensile strength, 27.2% elongation at break).


ABSTRACT
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.