Deposited structure design of epoxy composites with excellent electromagnetic interference shielding performance and balanced mechanical properties

Abstract

A series of well-designed electromagnetic interference (EMI) shielding epoxy (EP) composites with high mechanical properties are realized by constructing controllable deposited conductive network structures using a novel and facile processing technology named the modified in situ polymerization (MISP) method, which can provide an average EMI shielding effectiveness (SE) value of 36.8 dB at 2–18 GHz at a low loading of only 5 wt% silver-coated T-ZnO (T-ZnO/Ag) fillers. In comparison, the EMI SE value of the T-ZnO/Ag/EP composites prepared by the traditional in situ polymerization method and solution blending method can only reach 20 dB with 30 wt% T-ZnO/Ag content. Besides, the average EMI SE value of the composites prepared by the MISP method can reach 80.1 dB in the X band when the T-ZnO/Ag content increases to 20 wt%. The tensile strength can remain at 50.4 MPa at the same time. This work offers a feasible strategy for designing shielding materials with excellent EMI SE and balanced mechanical properties.