Recyclable conductive epoxy composites with segregated filler network structure for EMI shielding and strain sensing. (May 2020)

• Record Type: Journal Article
• Authors: Yuan, Dian; Guo, Haochen; Ke, Kai; Manas-Zloczower, Ica
• Is Part Of: Composites. Volume 132(2020)
• Publication Date: 2020-05
• Subjects: Segregated structure -- Epoxy waste -- Carbon nanostructures (CNS) -- Strain sensing -- Electromagnetic interference (EMI) shielding; Composite materials -- Periodicals; Manufacturing processes -- Periodicals; Composite materials; Manufacturing processes; Periodicals; 620.11805
• DOI: 10.1016/j.compositesa.2020.105837
• Languages: English
• ISSNs: 1359-835X

Abstract

Graphical abstract: Highlights: A segregated filler structure is formed in thermoset epoxy systems using a novel recycling technique. Improved mechanical properties and high electrical conductivity are obtained in the recycled epoxy composites at very low filler content. The recycled epoxy composites show stable and reproducible piezoresistive behavior with potential application in strain sensors. The brick-wall structure enables high EMI shielding in the recycled epoxy composites at low filler content. 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.