Mechanically strong, healable, and reprocessable conductive carbon black/silicone elastomer nanocomposites based on dynamic imine bonds and sacrificial coordination bonds

Abstract

Commercial conductive polysiloxane composites are usually unrecyclable and suffer from inherent poor mechanical properties. Herein, mechanically strong, healable, and reprocessable conductive carbon black (CB)/polysiloxane nanocomposites were prepared through incorporating dual crosslinks of imine bonds and Zn(II)-amino coordination bonds in elastomer networks. Following the energy-dissipating mechanisms of sacrificial bonds, the integration of coordination bonds led to the remarkable improvement of strength, stretchability, and toughness without compromising the self-healing ability or reprocessability. Furthermore, the sacrificial and reversible manner of coordination bonds in nanocomposites was studied in detail. In addition to enhancing the electrical conductivity of nanocomposites (i.e., 6.48 S/m at CB content of 12 wt%), the incorporation of CB could promote the rupture of sacrificial bonds and improve the energy-dissipating efficiency significantly.