Spider silk-inspired supramolecular polydimethylsiloxane network with prominent mechanical robustness for bifunctional flexible electronics

Self-healing and recyclable polymer elastomers are being developed to provide new prospects in building sustainable societies. Nevertheless, the synthesis of such materials still poses a significant difficulty because of the conflicting requirements between the self-healing ability and mechanical robustness for the dynamicity of crosslinks. Herein, a self-healing and recyclable supramolecular polydimethylsiloxane with outstanding tensile stress and ultrahigh mechanical toughness is constructed by synergistically incorporating dynamic disulfide bonds and multiple hydrogen bonds into a siloxane chain. The adipic dihydrazide (AD) bearing two hydrazide groups was appropriate introduced to provide multiple hydrogen bonding sites between polymer chains and improve the mechanical robustness of the crosslinked structure. The aromatic disulfide bonds contribute to shorter healing time due to the elevated dynamicity of the crosslinked network. The resulting elastomers exhibit high tensile strength (6.44 ± 0.24 MPa), distinguished toughness (37.00 ± 0.85 MJ m−3), superior elastic restorability, outstanding self-healing capability (∼86 %) and multiple recyclability. Furthermore, a bifunctional sensor based on this elastomer is constructed to monitor human motions and pressure changes, demonstrating the potential application in flexible stretchable electronics.