Biobased Polyurethane Materials with Self-Healing and Recycling Capabilities for Sustainable Applications in Triboelectric Devices

Abstract

Flexible triboelectric nanogenerators (F-TENGs) are prone to generating significant e-waste after disposal, and it is important to design more sustainable materials with self-healing and recyclable capability for application in F-TENGs. In this work, we first designed a biobased polyurethane elastomer (BPU-SS) with multiple dynamic networks contributed by the Diels–Alder (DA) reaction, disulfide bonds, hydrogen bonds, and van der Waals forces. The multiple dynamic networks endow the biobased elastomer with excellent self-healing properties (95% efficiency at 60 °C). Notably, using DA adducts as cross-linking units, the electronic components can be easily recycled from the elastomer in solution at room temperature after preheating at 120 °C for 5 min. Additionally, the elastomer also showed thermo-mechanical recyclability, e.g., it can be reprocessed into designable articles at 120 °C (10 MPa, 15 min). This elastomer was used to develop a self-healing and recyclable TENG (FR-TENG) with a power density of 0.52 mW/m². After self-healing, the output voltage recovery rate reached nearly 100% (36 V). This work provides a novel route for the development of sustainable, flexible friction nanogenerator materials.