A soft polyurethane foam adhesive with ultra-high and stable adhesion based on chemical coupling and mechanical interlocking

High bonding strength and adhesion stability performance adhesives are essential for many fields, including electronic packaging, and interface bonding, etc. However, ultra-high and stable adhesion imposes higher requirements on the structure and properties of soft adhesives. Herein, A ultra-high adhesion, adhesion stability performance soft adhesive was developed by soft polyurethane foam. PuFA x (polyurethane foam adhesive) demonstrated outstanding flexibility (maximum compressive strength of 62.86 kPa), and ultra-high adhesion strength (up to 81.42 MPa for Cu). The gas generated by the physical foaming of PuFA x serves as an internal driving force, facilitating the formation of a mechanical interlocking structure between the polyurethane chains and the substrates. Thus, it forms a synergistic effect with chemical coupling, further enhancing the bonding strength. In terms of environmental adaptability, PuFA x exhibited excellent solvent-resistant adhesion stability performance under harsh conditions, including exposure to solvents such as DMSO, CH 2 Cl 2 , C 2 H 5 OH, HCl, NaOH, NaCl, and H 2 O. Furthermore, PuFA x demonstrated outstanding stable adhesion properties even in high-temperature aqueous solutions with a temperature as high as 100 °C and throughout a prolonged aging process that can extend up to 12 months. The design strategy of PuFA x provided a new way to develop an outstanding soft adhesive candidate with ultra-high and stable adhesion.