Time‐dependence of piezo‐resistive behavior for polyethylene/foliated graphite nanocomposites

High‐density polyethylene (HDPE)/foliated graphite (FG) nanocomposites were prepared by blending HDPE with FG fillers. This nanocomposites exhibited much more distinct piezo‐resistive behavior (electric response under applied pressure), when compared with conventional conducting polymer composites. In this paper, the time‐dependences of piezo‐resistance, reproducibility and stability of the piezo‐resistive behavior for HDPE/FG nanocomposites are investigated. It is shown that the time‐dependence of piezo‐resistive behavior strongly depends on the fixed pressure and FG concentration. Under a lower fixed pressure, the relative resistance decreases with time, whereas the composite resistance increases with time under a higher fixed pressure. The shift of relative resistance changes more slowly at higher filler concentrations. The average ‘nanosheet’ separation in the nanocomposite changing with time under fixed pressures is the origin of the time‐dependent piezo‐resistive behavior.