Payne effect and Mullins effect of silica filled butadiene rubber nanocomposites vulcanizates and their unextractable gels

Rubber nanocomposites exhibit strain softening under large-amplitude oscillation shear and large-strain cyclic tension while the mechanisms remain unresolved. Herein we systematically investigate the Payne effect and Mullins effect of unfilled and silica filled butadiene rubber (BR) vulcanizates to clarify the impacts of crosslinking density, sol fractions, and filler content. During large-amplitude oscillation shear, the critical strain amplitude for the onset of Payne effect is closely related to storage modulus in the linear viscoelastic region. During cyclic tension deformations, the recovery hysteresis energy and accumulating softening energy are involved in the local deformation of the rubber matrix, which is promoted by the filler phase. These findings are illuminative for optimizing performance of rubber nanocomposite products by controlling the nonideal network structure of viscoelastic rubber matrix.

Automated summary

In this study, the Payne effect and Mullins effect of unfilled and silica filled butadiene rubber (BR) vulcanizates were systematically investigated. It was found that the critical strain amplitude for the onset of Payne effect during large-amplitude oscillation shear is closely related to the storage modulus in the linear viscoelastic region. In cyclic tension deformations, the recovery hysteresis energy and accumulating softening energy are involved in the local deformation of the rubber matrix, which is promoted by the filler phase. These findings provide insights for optimizing the performance of rubber nanocomposite products by controlling the nonideal network structure of the viscoelastic rubber matrix.