Advanced low-temperature self-healable bio-polyurethanes with double-alkane-tailed ringing units for applications in self-powered flexible control panels

Abstract

Elastomers with dynamic covalent bonds are typically used to develop self-healing flexible control panels, however, their self-healing efficiency is low at low temperatures which hampers the stable operation and durability of the control panels. This work used a new strategy to achieve low-temperature self-healing in bio-based polyurethane elastomers (PDLBE) by designing a dynamic van der Waals force network. The elastomers are synthesized by using biobased monomers containing a double-alkane-tailed ringing unit and show self-healing efficiencies close to 90 % even under low temperature (−20 °C), supercooled brine (30 % NaCl @ −20 °C), and alkali (pH = 14) conditions. In addition, the PDLBE exhibits rapid self-healing capability, superior elongation rate (12,000 %), and reprocessability. Both experimental and molecular simulation results indicate that the low-temperature self-healing properties are mainly attributed to the abundant vdW forces and self-plasticization generated by the double-alkane-tailed ringing unit. Subsequently, low-temperature triboelectric nanogenerator (LT-TENG) and LT-TENG-based flexible control panels are successfully made from the elastomers, showing a recovery of 97 % at − 20 ℃ and a stable output (∼13 mW/m²) at − 30 ℃ after damage and even after 1200 cycles. This study presents a novel route for the preparation of low-temperature self-healable bio-elastomers and may expand their application in TENGs and flexible control panels in harsh environments.