Abstract
Fifteen active filler-loaded unvulcanized rubber samples were prepared. The polymers used were the fractionated and the unfractionated cis-polybutadiene (Cis 4) and both ISAF (Vulcan 6) and HMF (Sterling L) types were used as fillers.
Tensile stress relaxation data were then obtained for those samples at temperatures from -30° to 80°C. The amount of strain applied ranged from 0.1 to 3.0.
Application of the blending law previously proposed to the experimental data appeared to be essentially successful, though the viscoelastic properties of the polymeric matrix were found to be progressively modified by the addition of fillers. The effective volume fraction of fillers estimated therefrom seemed to be practically the same as the real one in general.
It was then shown that the change in the viscoelastic properties of the polymeric matrix caused by the presence of fillers could reasonably be described by taking into account of the fact that each filler particle acts as a multifunctional cross-linking agent in and after mixing processes.
