Network reconfiguration and unusual stress intensification of a dynamic reversible polyimine elastomer

Reversible covalent bonds have been comprehensively reported to endow traditional crosslinked elastomers with reprocessability and recyclability. Herein, we prepared a polyimine elastomer (PIE) with abundant dynamic reversible imine bonds from small-molecular aldehydes and amines. More interestingly, we observed an unusual stress intensification phenomenon under constant strain during the typical tensile stress relaxation tests on PIEs. Reversible imine chemistry was revealed to control the stress relaxation and intensification, as well as to facilitate the restoration of network integrity. This unusual phenomenon reflects that structural reconfiguration is proceeding in dynamic reversible networks during deformation and determining the materials’ mechanical response to external deformation. [Display omitted] •Dynamic polyimine elastomers were prepared via imine condensation from small-molecular aldehydes and imines.•Unusual stress intensification was observed during tensile stress relaxation of polyimine elastomers.•Reversible imine chemistry was discussed as the cause of network reconfiguration and unconventional mechanical properties.