Changing the percolation threshold of a carbon black/polymer composite by a coupling treatment of the black

The change in percolation threshold of carbon black/polymer composite using coupling treatment was discussed. The polymer composite filled with a conductive filler became electrically conductive once the volume fraction of CB exceeded a certain critical value. The hydroxyl groups were expected to form hydrogen bonds with silanol groups, hydrolyzed from methoxysilane in the coupling agent. The amine salts formed by the reaction of amine with carboxyl decreased the energy needed for charge carriers to hop from conducting clusters. Analysis shows that the percolation threshold arised at an low CB content even in the case of unblended matrix composites.