Time, amplitude, and frequency dependence of the Payne effect a study on silica-filled styrene-butadiene rubbers

The study explores the Payne effect in silica-filled styrene-butadiene rubbers (SBR) and acrylonitrile-butadiene rubber (NBR). Dynamic mechanical tests in torsion were performed on SBR, unfilled and containing 25, 50 and 75 phr silica particles, and on a 60 phr silica-filled NBR to assess the influence of filler content, strain amplitude, and frequency on the Payne effect. The results indicates that a linear analysis of the nonlinear response is an acceptable approximation in the range of strain amplitudes considered here. Further, the Payne effect is reversible in nature, as the materials can recover their initial storage modulus after deformation. However, the recovery is slow, and the effect of multiple strain sweeps does not accumulate. The also study confirms the separability of strain amplitude and frequency effects, allowing for the construction of a Payne effect master curve