Phase Morphology and Conductive Properties of PBT/POE-g-GMA/PP/CNT Nanocomposites with a Tri-Continuous Structure via Thermal Annealing

In order to improve the conductivity of polymer composites and elucidate the relationship between the microstructure and conductivity, a series of PBT/POE-g-GMA/PP/CNT nanocomposites with a tri-continuous structure and low conductive percolation threshold were prepared by melt blending. Compared to PBT/PP/CNT composites, the PBT/POE-g-GMA/PP/CNT nanocomposites show better conductivity owing to the selective distribution of carbon nanotubes (CNTs) in the POE-g-GMA phase with the same CNT content. The increasing content of the CNTs and POE-g-GMA refines phase morphology, thus influencing the CNTs’ conductive path. Composites containing 10 wt % POE-g-GMA display the lowest conductive percolation threshold at 1.0 phr. In addition, the influencing mechanism of thermal annealing on microstructure and conductivity was methodically investigated. Thermal annealing can effectively enhance the rebuilding of CNT conductive networks and continuity of the POE-g-GMA phase on the premise of the original phase structure, decreasing the volume resistivity of nanocomposites. The nanocomposites obtained in this study possess excellent electrical properties alongside the potential to be a candidate material in fields of sensors, electromagnetic interference shielding, and so forth.