Rubber composites with high toughness, superior energy absorption and a fully retained electromagnetic interference shielding effectiveness

Tough rubber composites with stable electromagnetic interference (EMI) shielding effectiveness ( SE ) can be used as sealing components at the connecting parts of aerospace equipment because they attenuate EM waves, resist external damage, and absorb shock energy. However, the trade-off between high SE and outstanding mechanical properties—caused by the filler distribution and the topological structure of the crosslinked network—hinders the development of such rubber composites. More importantly, after being subjected to cyclic stress, their SE exhibits a marked degradation, significantly compromising their practical applicability. To address these issues, rubber composites with a unique structure—comprising a loose segregated network of carbon nanotubes, uniformly distributed conductive carbon black, and an evenly dispersed sulfur crosslinked network—are designed and fabricated. This structure imparts the resulting rubber composites with excellent SE (52.9 ​dB), high tensile strength (17.9 ​MPa), and exceptional elongation at break (408%). Remarkably, the volumetric energy absorption of the filled rubber composites (4.52 ​MJ ​m −3 ) is 5.94 times higher than that of the pure rubber composites (0.76 ​MJ ​m −3 ). Significantly, after 20 cycles of cyclic stress loading at 25% strain followed by thermal treatment, the composites maintain 100% of their initial SE . Therefore, these rubber composites hold enormous potential for use in EMI shielding sealing components.