Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing

Abstract We experimentally examine the thermo-resistive and thermo-piezoresistive sensitivity of multiwall carbon nanotube (MWCNT)/polypropylene random copolymer (PPR) nanocomposites processed via fused filament fabrication (FFF) process. The feedstocks were fabricated by melt blending neat PPR with a predetermined amount MWCNTs (either 4, 6 or 8 wt%) using twin-screw extruder. Thermo-resistive characteristics MWCNT/PPR composites measured under both constrained unconstrained heating from approximately 30-100 °C. For all MWCNT concentrations considered here, negative temperature coefficients resistivity (TCR) observed for heating, as consequence thermal fluctuation-induced tunneling at junctions. highest was composite lowest concentration (4 wt%) conditions, reporting TCR ?12,800 × 10?6/°C, which is higher in magnitude than that other polymer reported literature. Moreover, exhibit strong response tensile loading. 4 wt% loading, gauge factor (measured over 0–20% strain range) increased 27.8 to 52.3 when raised 30 °C 60 °C. Our results further evince i.e., high 395 at electron hopping, thermally-assisted activated mechanical deformation matrix, significantly increase thermo-piezoresistance this range. excellent study would enable development smart self-sensing strain/damage state.