Abstract
The mechanical properties of styrene butadiene rubber (SBR)/ethylene propylene diene monomer rubber (EPDM) conductive blends prepared by conventional mixed method were studied as a function of both blend ratio and high-abrasion furnace (HAF) carbon black (CB) contents. All measured mechanical characteristics, such as Young’s modulus, strain at break and stress at break, exhibit a transition at percolation threshold ( φ
c
), which was found to be dependent on the SBR/EPDM blend ratio. From the dependence of the electrical conductivity of SBR, EPDM and their blends filled with HAF CB on the volume portion of the filler, the percolation concentration ( φ
c
) was determined to be at the inflexion point φ
i
of the dependency. The elongation at break of the investigated composites was succeeded to connect to the percolation concentration by Novak et al. model and an empirical formula suggested by us and showed reasonable results.