Debond on command: Fast debonding by exothermic reaction due to microwave activation

Joining by adhesive bonding gains more interest for structural compounds, because there are many advantages in comparison to mechanical or thermal joining techniques. In addition to the environmental performance, gluing can increase cycle time in the process, while the substrates experienced no mechanical or thermal stress. The increasing applications require also a method for debonding for repairing and recycling processes. Particularly for structural adhesive bonding it does not exist today. The presented research on debondable adhesives includes exothermic reacting materials, which are inactive during the life cycle and can be activated by microwave radiation (MW). Ionic liquids (IL) have been used as microwave absorber and, additionally, can release heat energy during the decomposition through their positive enthalpy of formation. The endothermic reaction can be used to initiate the decomposition of the added blowing agent and oxidizer, which destroys the polymeric matrix and generate additionally a mechanical blowing effect.