Dielectric properties of carbon fiber filled low-density polyethylene

Carbon fiber (CF) filled low-density polyethylene (LDPE) matrix composites was prepared by means of the Hakke driver. The dielectric properties of the CF/LDPE composites as a function of the frequency and the volume fraction of CF were studied. The dielectric constants decrease slowly with increasing the frequency and rise gradually with increasing the CF contents in the composites. As the volume fraction of the CF is up to 0.20, an abrupt increase in the dielectric constant occurs, and accordingly electrical conductivity measured at low frequency increases rapidly at this volume fraction. The percolation theory and the simple concept of polarization in the capacitors are employed to explain these experimental results. (C) 2003 American Institute of Physics.