Water-Debondable Adhesive Polymer Networks Using Hyperbranched Polyglycerols

Debondable adhesives have emerged as a promising alternative for industries such as automotive and electronics, offering strong, yet reversible bonding. The limitations of conventional debondable adhesives include the harsh conditions required and the residue left behind upon removal that necessitates additional cleaning steps. Herein, we report water-debondable adhesives based on polyester-cross-linked hyperbranched polyglycerols (HPGs), which afford high adhesion strength and yet are debondable upon exposure to water. The advantages of HPG as adhesive precursors are the high valency of hydroxyl functionalities, low T_g, low viscosity, and the reversibility of the hydrogen bonding interactions that enable strong surface adhesion. HPG and pyromellitic dianhydride (PMDA) were cast and thermally cured to adhere aluminum substrates with an adhesion strength over twice that of a commercial epoxy adhesive. This high adhesion strength was maintained for 3 days under ambient conditions, after which the adhered samples were debonded after immersion in water at 90 °C. Thus, these adhesives exhibit both a high adhesion strength and a simple mechanism for debonding and could find utility in future sustainable manufacturing practices.