Dielectric losses in polyethylene/neodymium composites

Polymer/metal composite materials have good rheological properties due to the polymer matrix and superior electrical or magnetic properties through the conductive or magnetic filler. For this reason, they can be used in a number of industrial applications as electromagnetic shields or permanent magnets. This paper deals with the results of an experimental study regarding the manufacturing and characterization of composite materials containing low density polyethylene (LDPE) as matrix and neodymium (Nd) as filler, obtained by melt processing. The structure of composites, the loss factor measured in harmonic fields at frequencies between 1 mHz and 1 MHz and temperature between 30 and 80 oC and the relative and specific losses are presented and discussed in this paper. Both loss factor and specific losses vary with the frequency of the electric field, temperature and filler content. For certain values of the frequency, the loss factor and relative losses show maximum values which increase of the temperature and filler content. The specific losses decrease with temperature but increase with the filler content and frequency of the electric field. For frequency values close to 1 MHz the specific losses overlap the ones in copper conductors.