equal loading [9–11], it is also interesting to elucidate the
effect of types of filler on the mechanical properties of the
vulcanizates at the same hardness level. This is because
a specific hardness is required for numerous industrial
products. In this study, vulcanizates having the same
hardness were prepared by adjusting the amount of each
filler. Then, the mechanical properties of the vulcanizates
were determined. Also, the mechanical properties of
natural rubber vulcanizates filled with equal amounts of
carbon black, silica and montmorillonite clay (6 phr) were
compared. The degree of filler dispersion of all vulcanizates
was also examined and related to their properties.