Fabrication of basalt cotton/polytetrafluoroethylene (BC/PTFE) composite fiberboards with excellent dielectric properties over a wide frequency range

Abstract

To expand the field of application of basalt cotton (BC) and BC-based composites, BC/PTFE (polytetrafluoroethylene) composite fiberboards were prepared by embedding a PTFE filler into a BC matrix using a wet method. The mechanical and dielectric properties of the composites were investigated. The experimental results indicate that the composites prepared using a concentration greater than 4 wt% PTFE could maintain the structural stability of the fibers in BC under high stress. The dielectric constant of BC/PTFE composites exhibited good frequency stability over a wide frequency range. The PTFE filler facilitated a decrease in the dielectric constant and dielectric loss, and the dielectric loss values of all composites remained below 0.007. The dielectric constants of the BC/PTFE composites were stable over a wide temperature range, and when PTFE content increased, the constant values were large within a stable temperature range.