The dynamic properties of carbon black loaded natural rubber vulcanizates. Part II

Abstract The dynamic shear modulus at very high strains, (G∞), of carbon black filler loaded vulcanizates is regarded as due to the product of two factors: (a) a hydrodynamic interaction due to filler particles, and (b) a second factor for which evidence is given suggesting that it arises from a few strong linkages which are known to link filler particles to the matrix. Experimentally a measure of (a) has been obtained from model vulcanizates using glass spheres as the filler, and of (b) from equilibrium swelling measurements on rubber vulcanizates containing carbon black. Quantitatively, the difference between the shear modulus of the pure gum vulcanizate, Gpure gum, and G∞ can be explained by these measurements.