Programming dynamic imine bond into elastomer/graphene composite toward mechanically strong, malleable, and multi-stimuli responsive vitrimer

A combination of malleability, supramechanical properties and multi-stimuli response into catalyst-free and commercially available polymer-based networks is particularly attractive to extend the realm of thermally malleable polymers. Toward this goal, herein we demonstrated a paradigm by introducing dynamic imine bonds into styrene-butadiene rubber (SBR)/graphene composites. SBR was firstly grafted with aldehyde groups and then cross-linked with p-phenylene diamine and it-modified graphene through imine condensation between aldehyde and amino groups. The crosslinked networks were able to alter their topologies via imine exchange reactions in both the bulk network and SBR-graphene interphase in the absence of catalyst, enabling them to be recycled and reshaped under heating or IR irradiation. The incorporation of graphene led to spectacular improvements on the mechanical properties of vitrimer composites, and the mechanical properties could be tuned through solid-state drawing. The relationships between morphological structure and dynamic properties as well as mechanical properties of the vitrimer composites were addressed.