Effect of sacrificial bond on molecular dynamics and rheological behavior of hybrid butadiene-styrene-vinylpyridine rubber vulcanizates with reversible sacrificial network

Due to the improvement of strength and toughness at the same time, construction of reversible sacrificial bond network has attracted extensive attention to realize the high performance and functionalization of rubber materials. However, the research on the viscoelastic behavior of vulcanized rubber with reversible sacrificial bond network lags behind seriously. In this work relaxation kinetics, linear rheological behavior and nonlinear rheological behavior of hybrid crosslinked butadiene-styrene-vinylpyridine rubber (VPR) with reversible Zn 2+ -pyridine coordination bond were investigated in detail. It was found that, the tensile results under small strain were more conducive to reflect the contribution of sacrificial bond after sequential tensile-recovery process than those under large strain. Although sacrificial bond could affect both G' and G" at low temperature, the contribution of it to G" was more prominent. When the temperature was higher than the dissociation temperature of Zn 2+ -pyridine coordination bond, the sacrificial bond could only affect G" , which was due to the fact that the pyridine group was equivalent to the graft on VPR backbone and acted as dangling chain. In addition, the destruction and reconstruction of coordination bond was the dominant factor in modulus recovery. Graphical