Preparation and Properties of Multiple Dynamic Crosslinked Poly(siloxane-urethane)

Graphical In this study, we introduced hydrogen bonds, metal coordination bonds, π–π bonds, and reversible rings into the poly(siloxane-urethane) system for the first time, achieving a self-healing efficiency of 86.6 % and a mechanical strength of 9.68 MPa when the soft segment (PDMS-OH) addition amount was 1.0 g. This significantly enhanced the mechanical properties of the material while ensuring excellent self-healing efficiency. Self-healing poly(siloxane-urethane) materials have garnered significant interest among researchers, owing to their superior resistance to high and low temperatures, solvents, corrosion, and biocompatibility. Nevertheless, most existing self-healing poly(siloxane-urethane) materials face challenges, including limited repair conditions and the challenge of balancing mechanical properties with repair efficiency. In this research, we introduced hydrogen bonds, metal coordination bonds, π–π bonds, and reversible ring structures into the poly(siloxane-urethane) system through molecular chain structure design, successfully developing a multi-dynamic cross-linked poly(siloxane-urethane) (PU-Si), a development rarely reported in prior studies. This study examines the impact of varying amounts of hydroxyl-terminated polydimethylsiloxane (PDMS-OH) on the properties of PU-Si. The results indicate that PU-Si, regardless of the amount of PDMS-OH added, can self-healing under conditions of heating at 60 °C, and exposure to ultraviolet and infrared radiation. Specifically, when the PDMS-OH addition reaches 1.0 g, the material exhibits superior mechanical properties and self-healing efficiency, achieving a mechanical strength of 9.68 MPa and a self-healing efficiency of 86.6 %. This material shows significant application potential in areas such as electronic skins, flexible sensors, and brain-computer interfaces.