Water-based polyurethane adhesive films with enhanced bonding strength capable of in situ and high-efficient deposition on metal surface

Producing high-efficient, low-cost, and green water-based adhesives with enhanced bonding performance still remains highly challenging. In this study, waterborne polyurethane (WPU) adhesive films long-term stability are in situ fabricated on a metal substrate by facile high-efficiency preparation method known as demulsification-induced fast solidification (DIFS). The strength of was constructing multiple cross-linked structures between polycarbodiimide (PCD) WPU, which determines the cohesive force films. obtained for WPU-L/PCD-0.1 (L: polycaprolactone, 0.1 represents PCD mass fraction to emulsion) film is>2.40 ± 0.21 MPa (stock-break failure mode) at room temperature 120 d, satisfactory stable connections. Moreover, exhibits an excellent water-resistance because hydrophilic carboxyl groups WPU form cross-linking network eliminate groups. We expect that new type will be useful protection coatings applications.