Enhanced EMI shielding effectiveness of green Eucommia ulmoides gum composites through heterogeneous and crystalline structures

In order to mitigate the increasing severity of electromagnetic interference (EMI), it is imperative to develop advanced rubber composites. Despite recent advancements in structural design and filler hybridization for enhancing their EMI shielding performance, challenges persist in terms of suboptimal mechanical properties and intricate processing techniques. To overcome these limitations, bio-based Eucommia ulmoides gum (EUG) composites with segregated network structures were fabricated by simple mechanical blending, capitalizing on the characteristics of highly cross-linked rubbers with restricted molecular chains. Highly cross-linked EUG (HCE) effectively segregated the conductive fillers into the EUG phase, while the crystallization of EUG promoted the dispersion of fillers within the amorphous region of the EUG. Therefore, a highly efficient 3D conductive network was formed due to the segregated structure and crystallization, enabling the EUG/HCE/CNT composite to achieve an exceptional shielding effectiveness (SE) value of 83.0 dB with a high absorption loss ranging from 8.2 GHz to 12.4 GHz. [Display omitted] •Achieving efficient electromagnetic shielding using simple mechanical technology.•Enhanced electromagnetic shielding performance through volume exclusion effect.•Highly cross-linked rubber facilitated the formation of segregated structure.•The synergistic effect of segregated structure and rubber crystallization.•Reinforcement effect for composites due to interfacial cross-linking.