Synthesis and characterization of silver–thiolate dynamic crosslinking waterborne polyurethane with room-temperature self-healing properties

Abstract

Waterborne polyurethanes (WPUs), commonly used as coatings and adhesives, produce microcracks when suffering from severe environmental stimuli or continuous mechanical loads. So far, there have only been limited self-healing functional groups, such as disulfide bonds, or Diels–Alder reactions, utilized in WPUs. Herein, we have prepared a novel self-healing waterborne polyurethane (SHWPU) by introducing silver–thiol coordination interactions, which exhibit excellent self-healing performance. WPU–Ag@S-0.50 with microcracks could recover to its original state at room temperature within 30 min. The self-healing efficiency in terms of its tensile strength is 98.69%, demonstrating that introducing silver–thiol coordination interactions is an effective strategy to realize self-healing.