Low melting point alloy segregated network construction in thermosetting polymer matrix for the electromagnetic interference shielding and thermal conductivity enhancement

With the development of high power, miniaturization and integration of electric devices, materials with effective electromagnetic interference (EMI) shielding and high thermal conductivity have become a hot topic. In this paper, cross-linked epoxy microspheres (CEMs) were firstly synthesized by precipitation polymerization, and then the CEMs were physically mixed with low melting point alloy (LMPA) SiBi58. Finally, the segregated epoxy/SnBi58 composites were prepared via hot-pressing technique. The SEM results showed that the aggregated SnBi58 particles formed a continuous network microstructure in the epoxy matrix, which was beneficial to the conduction of electrons and phonons. The epoxy/SnBi58 composites with 50 vol% alloy presented an outstanding electromagnetic interference (EMI) shielding effectiveness (SE) of 72 dB at 10.5 GHz and a satisfactory thermal conductivity of 1.6 W mK(?1). Furthermore, this study demonstrated the potential application of LMPA in both thermal management and EMI shielding materials in future, and also widened the application of epoxy resin.