Percolation in electrical conductive polymer / filler systems. I: Density/ filler curves according to a new thermodynamic percolation model

This work deals with the conductivity of polymer/filler‐mixtures, with the conductive filler particles of colloid size. For the interpretation of the conductivity course in such systems Wessling recently proposed a new thermodynamical percolation model, the so‐called “dynamic boundary model.” A consequence of the dynamic boundary model is a fixed picture for some properties of the mixtures, i.e., the density should vary in a defined manner according to the theoretical assumptions of the model. The current paper first gives a short description of the percolation process according to the dynamic boundary model. Second, the derivation of the density/filler concentration curves according to the assumption of this model is given. Third, a comparison is made between calculated and experimentally determined density/filler concentration curves. It is shown that the dynamic boundary model cannot account for the experimentally observed density curves.