Strain hysteresis and Mullins effect of rubber vulcanizates with a reversible sacrificial network

The incorporation of reversible sacrificial bonds is an important strategy for enhancing the mechanical properties of elastomers. However, the research on the viscoelasticity of vulcanized rubber with a reversible sacrificial bond network lags seriously. In this paper, the effects of metal coordination bonds on the mechanical properties of butadiene-styrene-vinylpyridine rubber vulcanizates (VPR) were systematically investigated. The experimental results showed that lower temperature and higher strain rate under smaller strain were advantageous in reflecting the significant contribution of sacrificial bonding. Compared with the conventional rubber nanocomposites, the sacrificial bond enhanced the energy dissipation while also improving reversible hysteresis energy and its proportion, revealing the origin of better self-healing and damping properties. The high-temperature rearrangement of sacrificial bonds promoted not only the recovery of mechanical properties, but also the recovery of covalent networks. The evolution mechanism of the network structure and viscoelasticity research under different thermal-mechanical coupling conditions could help to control the rubber network structure, providing a promising method for the regulation of the nonlinear behavior of rubber composites.