Transformation of the strengthening and toughening modes of a poly(urethane) elastomer with hard segments of Ti3C2 MXene and its excellent triboelectric performance

Abstract

It is a universally accepted strategy to modulate the soft and hard segments of polymer chains to achieve good elastomers. Different from other reports, in this work, Ti₃C₂ MXene was selected as the hard segment to prepare a poly(urethane) (PU) elastomer with integration of the structure and function. In this process, different effects of the hard segment and nanofiller of MXene and the transformation of the strengthening and toughening modes of PU with the hard segment of Ti₃C₂ were confirmed. The addition of a small amount of Ti₃C₂ resulted in the formation of balanced covalently crosslinked networks and increased the strength and toughness of the elastomer. Further addition of 4,4′-diaminodiphenyl disulfide (4AD) improved its toughness by enhancing its hydrogen bonding. The resulting PU exhibited exceptional elastomeric properties with a tensile strength of 22.1 MPa and toughness of 334.3 MJ m⁻³. The dynamic breaking and reformation of hydrogen bond motifs and the dynamic dissociation of disulfide bonds endowed the PU elastomer with an excellent damping capacity (about 65%), crack tolerance, and self-healing properties. After 6 hours of contact at 60 °C, the healing efficiency of two fracture sections approached 89.5%. Additionally, the good electrical conductivity of the hard segment Ti₃C₂ and the enhanced permittivity endowed the elastomer with excellent triboelectric performance. This work provides a general method to synthesise excellent PU elastomers with the integration of the structure and function by only modulating the hard segments.