Application of two phase model to linear viscoelasticity of reinforced rubbers

A two phase model proposed for accounting for linear viscoelasticity of polymer nanocomposite melts [14] is applied to rubbers filled with nanoclay and conventional fillers (carbon black and silica) to probe mechanisms of the fluid- and the solid-like behaviors beyond the terminal flow region. This model shows strong applicability in linear rheology beyond terminal region for a variation of filled rubbers. Characteristic moduli of the “filler phase” from different filled rubbers could collapse onto a master curve, which reveals a jamming transition with increasing filler concentration across the percolation threshold. The strain amplification effect and reduced characteristic moduli of the “filler phase” are discussed within the framework of the cluster-cluster aggregation model.