Electrical Percolation Model of Ternary Carbon Filler Mixture in Polymer Blends

A model was proposed for predicting the electrical percolation of ternary carbon filler mixture in polymer blends based on excluded volume theory. 2D and 3D models were used to describe the percolation model. Carbon black( CB),tangled carbon nanotubes( t-CNTs) and aligned carbon nanotubes( a-CNTs) were used as carbon-type conductive fillers. Taking polycarbonate( PC) / styrene-acrylonitrile( SAN)( 70 ∶ 30,mass ratio) and PC / polyphenylene oxide( PPO)( 70 ∶ 30,mass ratio) as the matrices,the equation developed from the percolation model is corrected by measuring the percolation thresholds of each carbon filler in polycarbonate and polymer blends. Predictions from the model match the conductivities well,proving the suitability and usefulness of the model. For those polymer blends with the same matrix polymer,the equation can be obtained by the ratio of the percolation threshold of one carbon filler in the polymer blend to that in the matrix polymer.The model can provide an important theoretical basis for structure designing and predicting the electrical properties of conductive polymer composites.