Strong, Removable, and Photoluminescent Hyperbranched Polyamide-amine Hot Melt Adhesive

The development of adhesive technology is gaining increasing attention in machinery, electronics, aviation, and other fields. However, traditional adhesives are difficult to be peeled and removed after cross-linking and curing due to the limited solubility in common solvents, which causes pollution and damage to the surface of the adherend. In this work, we synthesized random hyperbranched polyamide-amine hot melt adhesives through Michael addition of 1,8-octanediamine and N,N’-methylene diacrylamide (ODA-RHP HMA). Owing to the presence of various polar groups, ODA-RHP HMA exhibited robust lap shear strength to different substrates, including glass (6.6 MPa), ceramics (10.3 MPa), steel (11.5 MPa), and aluminum (11.8 MPa). Due to the hydrogen bonds in ODA-RHP, the HMA demonstrated intrinsic self-healing ability, which can be used repeatedly when being subjected to cyclic heating and cooling. Since ODA-RHP HMA can be swollen or dissolved in ethanol, the adhesives can be easily removed through erasing. In addition, ODA-RHP exhibited aggregation-induced luminescence due to the tertiary amine structure in the molecular structure of ODA-RHP, which can be used in the field of cultural relics restoration.