Structure-concentration equivalence in carbon black reinforcement of elastomers. III. Application to tensile strength

Using carbon blacks of constant specific surface area and surface chemical characteristics, but differing in degree of structure, it is shown that tensile strength, elongation at break and rupture energy are functions of the product av2, where v2 is the volume concentration of carbon black and a is a structure dependent factor. Moreover, reductions of failure data to a common effective filler concentration are accomplished with the identical structure factors used earlier in modulus reductions. The values of the structure factors are linearly related to the dibutyl phthalate (DBP) absorption of carbon black, when care is taken to equalize the packing density prior to conducting the DBP test.