Recyclable conductive epoxy composites with segregated filler network structure for EMI shielding and strain sensing

Abstract

Forming a segregated conductive filler network at polymer particle interfaces enables the fabrication of high-performance conductive polymer composites at low filler content. However, this method is not applicable to thermosets that are not melt processable. Here, we report a facile and effective strategy to build a segregated filler network at epoxy waste particles and convert the system into a high-performance conductive composite. First, the permanent network in the epoxy waste is converted into a dynamic one via catalyst infusion. Subsequently, using an interface design strategy, branched carbon nanotubes (CNS) are introduced in the recycled epoxy system to form a segregated structure at the epoxy particle interfaces by compression molding. The resultant composites have excellent tensile properties, very low electrical percolation threshold and high electrical conductivity at low filler loading. This strategy enables the recycling of epoxy waste for the fabrication of high-performance composites for strain sensing and EMI shielding.