Effects of additives of organically modified montmorillonite and Octosilicate in a silica reinforced tire tread mixture

Dual filler networks of spherical and layered particles on the example of elastomer-reinforcement with silica, doped with a small quantity of organically-modified layered silicates (Octosilicate or montmorillonite) in the mass ratio of 80 to 3 were investigated, as well as the influence of the organic-modifier on the mechanical properties of the rubber composites. Synergies with interesting mechanical properties for technical rubber applications were found, but surprisingly only for the system that contains organically modified octosilicate, attributed to a higher extent of exfoliation/intercalation and related to a higher and more homogeneous surface modification than for organically modified montmoriilonite under the chosen experimental conditions. Shear modulus measurements on concentration series' allowed the determination of scaling exponents for the reinforcement that are well described by the cluster-cluster aggregation model. This also suggests integration of the relatively large layers of montmorillonite or Octosilicate during the early stages of the flocculation process because of the increased collision probability of particles of different sizes over particles of same size.

Automated summary

This study investigated dual filler networks of spherical and layered particles in elastomer-reinforcement with silica, doped with organically-modified layered silicates, to explore the influence of the organic modifier on the mechanical properties of rubber composites. It was found that the system containing organically modified octosilicate exhibited higher exfoliation/intercalation and more homogeneous surface modification, resulting in interesting mechanical properties suitable for technical rubber applications.