High‐Strength, Self‐Healing, and Conductive Polyurethane Enabled by Double Crosslinking Network for Advanced Multifunctional Strain Sensors

Flexible and stretchable conductive elastomers have broad application prospects in health monitoring, wearable flexible sensor, and information encryption. However, the current electronic conductors have conductive fillers easily fall off, conductive performance is unstable, and other problems limit their practical applications. Therefore, developing a conductive elastomer that combines high mechanical properties, good compatibility of the conductive filler with the substrate, and stable conductivity remains a significant challenge. In this thesis, a self-healing conductive elastomer with excellent mechanical properties, conductivity, and good compatibility of the conductive filler with the substrate is successfully synthesized by introducing high-density hydrogen bonding and dynamic disulfide bonding into the polyurethane network with the addition of a high-performance conductive filler, conductive carbon black (Super P). It possesses a stable conductivity of 8.4 × 10^-4 S cm^-1 at room temperature, a tensile strength of 27.5 MPa, and an elongation at break of 578.7%, as well as good resilience and 46% self-healing efficiency. Wearable strain sensors, designed for durability, stability, and high sensitivity, are ideal for detecting human motion, monitoring rehabilitation training, and enabling encrypted information transmission. This study provides new ideas for developing high-performance, self-repairable, and recyclable flexible conductive materials, which promotes the development of wearable electronic devices.