Extension of effective medium theory to three‐component system—two conductive particle types in the polymer matrix

A foundation is presented for the extension of the normal effective medium theory (for a two-component system (filler and polymer matrix)) to a three-component system (two filler species and matrix). No experimental test of the improved theory is made here, but some general trends are confirmed by other experiments. The theory is sufficiently general to allow the second filler component to represent a particle of the same composition as the first filler component but of a different size, or of the same size but of a different composition. Important satellite derivations are included.