The Study Of PI/CNTs Composite Material Based On Electrical Properties And Thermally Stimulated Current

Since carbon nanotubes (CNTs) were found in 1991, it has been a research focus by engineers for its excellent electric and mechanical properties. Polymer/CNTs have a widely variety of applications in many domains such as electrostatic elimination, electromagnetic shielding, printed circuit board (PCB), and so on.In the paper, polyimide/carbon nano tube (PI/CNTs) are tested through SEM characterization on mircro/nano structure, and also tested average breakdown strength, volume resistivity and dielectric spectra. CNTs vitally affected the property electric of composite film. When the content of CNTs is low, conducting particles can't form a conductivity network throughout the polymer matrix, average breakdown strength and volume resistivity maintain a high level; while the content of content of CNTs increases, a conductivity network forms, the electrical breakdown strength and volume resistivity decline sharply and the transition appears from insulation to semiconductor in 0.6wt%. Dielectric Spectra indicates that the existence of CNTs restrains the dipole orientation polarization.In the paper, PI/CNTs are measured under different testing conditions including pole field, pole temperature, pole time, heating rate, and so on. In addition, Gauss fitting is applied to separate TSC curve peak, and compute activation energy parameters. The charges injected in sample grow dramatically with the increase of pole field, meanwhile the higher the temperature, schottkey emission enhances, the more charges in sample, and the probability captured is bigger. The appearance of peakβis greatly affected by pole time. The activation energy of peakβfor PI/CNTs is between 0.34eV to 0.61eV, for peakρis 1.03eV to 1.56eV. It turns out that more traps are introduced by inorganic nano particles, can be easier to capture charges, and the mobile charges are constrained by traps. For pure PI the depth of charges injected into the sample are deeper in the same condition relative to nano sample, the electrons in traps transfer directionally after simulated, while for nano-sample, electrons are restrained by traps.