Preparation and conductive properties of polycaprolactone‐grafted carbon black nanocomposites

Polycaprolactone‐grafted carbon black (CB ‐g‐ PCL) nanocomposites were prepared by surface‐initiated ring‐opening polymerization of ε‐caprolactone on the surface of CB. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), atomic force microscope (AFM), X‐ray diffraction (XRD), and polarizing optical microscope (POM) method were employed to characterize the resultant CB ‐g‐ PCL. The effect of temperature on resistivity of polycaprolactone‐grafted CB (CB ‐g‐ PCL) nanocomposites was investigated and compared with that of mixture of CB and PCL. It was found that CB ‐g‐ PCL nanocomposites exhibited positive temperature coefficient (PTC) phenomena between 48 and 51°C, and negative temperature coefficient (NTC) phenomena and between 51 and 54°C. The prepared CB ‐g‐ PCL nanocomposites have the potential to be temperature‐dependent switch materials.