Influence of ball milling on the electrical properties of epoxy composites filled with carbon nanofibers

The article is devoted to studying the effect of ball milling of carbon nanofiber filler on the electrical properties of epoxy composites. One of the new possibilities for controlling the electrical properties of epoxy composites based on CVD-grown carbon nanofibers has been introduced using high-energy ball milling of the carbon nanomaterial. The influence of milling time on the grain size of carbon nanofiber powder was determined. The carbon nanofibers were characterized using low-temperature nitrogen adsorption, transmission electron microscopy, optical sedimentation analysis, and other methods. The conductivity, permittivity, and loss tangent of composite materials based on bisphenol A resin and carbon nanofibers were determined in a frequency range of 0.09 Hz to 1 MHz. It was established that the electrical properties of epoxy/carbon nanofiber composites depend significantly on the filler particle size formed during milling, due to the predominant contribution of interface polarization. Ball milling of such filler can be applied as one of the methods to improve the electrical properties of epoxy composites.