Mechanical, Thermal, and Electrical Properties of Epoxy Monolith Sheets Containing Carbon Black

Conductive pastes have been used to bond semiconductors and create electrical circuits, but in recent years their use has expanded to include flexible substrates used in portable and wearable electronic devices that require high stretchability. Conductive pastes using metals, carbons, etc. have problems such as the need to add large amounts of filler and the insufficient mechanical strength and poor heat resistance of the binder polymer material. Recently, epoxy monolith as a new material has been developed to achieve high strength and elongation by introducing a porous structure into cured epoxy resin. In this study, we demonstrate that carbon black (CB), which is added as a conductive nanofiller during the manufacturing process of epoxy monoliths, segregates within the framework of the epoxy monolith and forms conductive paths with a three-dimensional continuous structure. We investigated the structure and mechanical properties of the CB-containing epoxy monolith sheets and subsequently characterized their electrical and thermal conductivity. Furthermore, we clarified the change in electrical resistance when tensile stress was applied to the monolith sheet.