Correlation between rheological and electrical properties of polyamides filled with carbon black

The electrical properties of a polyamide filled with carbon black (CB) are due to the formation of a percolated CB network throughout the matrix. In a former study, we have shown that the quality of the network was related to the processing conditions used during the mixing process. This quality was assessed by the evolution of loss and storage modulus during strain sweep experiments. In the present paper, we perform simultaneous rheological and electrical measurements in order to get more information on the relationships between CB network structure and resistivity. We show that all the compounds can be classified into two different families, according to their electrical properties, and that it is possible, at fixed CB content, to move from one family to the other by modifying the mixing conditions.