Superposition approach to the dynamic-mechanical behaviour of reinforced rubbers

- Superposition approach for the dynamic moduli of reinforced elastomers is proposed.
- Rubber matrix is split into free chains and chains localized on filler surfaces.
- Dynamics in a broad frequency range for a broad class of fillers is investigated.
- Scaling characteristics of a localized network layer are extracted.
- Dynamics of localized chains depends strongly on the type of filler.

The main goal of present work is to study the dynamic viscoelastic properties of reinforced elastomers with a help of a recently developed superposition approach. To investigate the influence of the filler surface characteristics on the viscoelastic properties, a number of rubber compounds, based on a solution-polymerized styrene butadiene rubber and different types of fillers, was chosen. The master curves for the small strain storage E′(ω) and loss E″(ω) moduli were constructed at a reference temperature of 0∘C with a help of a self-developed shifting procedure based on the time-temperature superposition principle. To fit the master curves for reinforced elastomers in the whole range of frequencies over many decades, we propose to split the polymer matrix into two fractions. One fraction contains the free network chains far away from the filler particles, while the other fraction is composed from the chains localized near and on the filler surface. Such superposition approach allows to extract the characteristics of a fully localized polymer layer with a changed dynamic-mechanical behaviour. Importantly, based on the scaling behaviour of localized layer we show that the surfaces of studied fillers can impose quite different constraints on the rubber chains.

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