Modeling of dynamic-mechanical behavior of reinforced elastomers using a multiscale approach

- Multiscale approach for viscoelastic properties of reinforced rubbers is developed.
- It allows to fit the dynamic moduli over nearly 20 decades of frequency.
- Four frequency regimes based on physically-motivated models are observed.
- Characteristic relaxation times for each dynamic regime are identified.
- Localization of polymer chains on the filler surfaces is quantified.

The investigation of the molecular mobility of polymer chains and networks in the presence of active fillers such as carbon black or silica presents a big interest for the physics of reinforced rubbers. A better understanding of the physical characteristics of the filler-rubber interface is necessary to improve the overall macroscopic properties of these elastomers. The main goal of our work is to develop a physically based multi-scale approach for description of the viscoelastic properties of reinforced elastomers. Rubber compounds, based on a solution-polymerized styrene butadiene rubber filled with precipitated silica, were investigated. Dynamic-mechanical experiments were carried out in a wide range of temperatures to construct master curves for the small strain storage E′(ω) and loss E″(ω) moduli for nearly 20 decades of frequencies at a chosen reference temperature. The developed multiscale theoretical approach allows to analyze the master curves across the 20 decades of frequencies and to investigate the effects of the filler particles on the relaxation processes in simple rubber compounds at different time scales.

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