Didier Long

Filler–elastomer interaction in model filled rubbers, a 1H NMR study

Abstract 1 H NMR experiments on filled rubbers allow the observation of two features: the introduction of supplementary topological constraints by the fillers, and a layer of immobilised segments at the particle surface. In order to assess the role of the filler–elastomer interaction on the local chain dynamics, silica filled elastomer model systems were prepared. The synthesis methods used allowed us to test vastly different interaction strengths. It is shown that in the case of a weak interaction, the influence of the fillers is small, whereas a strong anchoring at the interface leads to an increase in the density of the topological constraints. The latter is correlated to a layer of highly immobilised segments whose thickness decreases with temperature. This layer is seen as a glassy shell.

Fatigue Behavior in Filled Natural Rubber: Study of the Mechanical Damage Dynamics

Rupture dynamics in reinforced elastomers is a much more complex process than in pure elastomers due to the intrinsic heterogeneous mixture of a rubber matrix with filler particles at submicronic scale. In the case of natural rubber, an additional source of heterogeneity is the strain-crystallization effect. How rupture dynamics and crack path are affected by filler particles and strain-crystallization is still a matter of debate. Actually, understanding how rupture dynamics and crack path are correlated to each other is probably an important key in order to improve long time resistance of reinforced rubbers.