Piezoresistive Characterization of Polyethylene Terephthalate-Graphite Composite

摘要

This study investigated the mechanical properties as well as electrical resistivity and piezoresistivity of the polyethylene terephthalate (PET)-graphite composite. The effects of graphite content, loading type, and loading rate on the performance of PET-graphite composite were investigated. Test results showed that the compressive and flexural strengths of the composite decreased rapidly as the graphite content was beyond 12 %. The electrical resistivity of the composite decreased from 3.5 × 10~8 Ω • cm to 2.2 × 10~3 Ω • cm as the graphite contents increased from 8 % to 12 %. The graphite content for the conductive percolation threshold of the PET-graphite composite was determined to be 13 %. The PET-graphite composite was sensitive to low compressive stress. When the compressive stress reached 0.7 MPa, the fractional change in the resistivity could reach 10.5 %. The piezoresistivity of the PET-graphite composite was significantly influenced by the loading rates. The field test indicated that the composite was able to detect the traffic effectively.