Bridge-graphene connecting polymer composite with a distinctive segregated structure for simultaneously improving electromagnetic interference shielding and flame-retardant properties

With the development of modern electronic technology, there is an urgent demand for the fabrication of multifunctional composites with electromagnetic interference (EMI) shielding and flame-retardant properties. Herein, a novel microcapsule structure is formulated by modifying the hydrophilicity of polypropylene (PP) micro-powder surface and wrapped with graphene oxide to modulate the distribution state of multi-walled carbon nanotubes (MWCNTs). The modified PP/reduced graphene oxide/MWCNTs (mPP/RGO/MWCNTs) composite with a distinctive segregated structure is obtained by hot-pressing of the microencapsulated PP micro-powder. The influence of the contents of MWCNTs and RGO on composite’s EMI shielding and flame-retardant properties are further investigated. Interestingly, the results show remarkable synergistic effect between MWCNTs and RGO, enhancing the electrical conductivity and EMI shielding property of the composites. Moreover, the segregated structure of mPP/RGO/MWCNTs composite enhances EMI shielding and flame-retardant properties compared with pure PP and mPP/MWCNTs. Therefore, this work provides new insights into the rational design of EMI shielding polymer composite with segregated structures to realize high EMI shielding performances and good flame-retardant properties.