Piezoresistive segregated polymer composites with high sensitivity of electrical response to mechanical impact were developed and are suitable for use as sensors. The method was proposed for creating a segregated composite structure by combining elastomeric rubber particles (RP) with three types of thermoplastic components: ethylene vinyl acetate copolymer (EVA), butyl rubber (BR), and polyvinyl butyrate (PVB). They acted as adhesive components connecting the elastomeric particles into the continuous matrix. A conductive hybrid filler of carbon black/carbon nanotubes was preliminarily introduced into EVA, BR, and PVB so that they formed a conductive segregated structure in the composites in the form of a framework around the rubber particles. The gauge factor (GF), which is the main indicator of piezoresistivity sensitivity, had high values, varying from 615 to 92, depending on the type of adhesive component. The composites demonstrate a high and stable electrical response to compression stress during cyclic testing in the measured range of 0.007–0.14 MPa, and in the strain range up to 1.5%. Piezoresistive characteristics were studied in the temperature range from −40 °C to +50 °C with the BR adhesive component, which, like RP, retains its elasticity down to −60 °C. The composites show stable electrical response over the entire temperature range and are suitable for use as sensors with prominent characteristics for detecting mechanical forces across a wide temperature range.
Mamunya et al. (Wed,) studied this question.