Abstract :
[en] Since their emergence in the early twentieth century, adhesive technologies have largely supplanted traditional joining methods such as screws and rivets due to their superior mechanical properties. This advancement enabled the integration of diverse materials, creating composite materials that allow for more compact, lighter, and better-sealed structures, with enhanced resistance to environmental factors. These improvements have significantly affected energy consumption, carbon footprint, and production costs, particularly in transportation.
Despite these advantages, adhesive technologies face a key challenge: the permanence of the bond, which limits reuse and recycling, leading to increased waste and material downgrading. To address this, reversible or debondable adhesives have been developed, which allow component disassembly and reuse of the material at their original value. Various debonding technologies, from van der Waals-based adhesives to those that respond to electrical currents, have been explored, yet no universal solution has emerged, especially for structural bonding that balances ease of implementation and mechanical integrity of adhesively bonded joints.
This thesis introduces a novel debonding solution inspired by flame retardancy. We repurpose flame retardants, exploiting their ability to swell under heat stimuli to induce debonding. The study examines several flame-retardant systems Ammonium Polyphosphate (APP) in two different forms, Melamine Polyphosphate (MPP), Organophosphorus Flame Retardants (PCO 900), and Expandable Graphite (EG) and their effects on the mechanical properties of bonded structures, both pre- and post-debonding.
In parallel with the mechanical study, each system is characterized and thoroughly investigated to provide a comprehensive understanding of the chemistry behind the debonding mechanisms, extending beyond traditional mechanical studies commonly found in the literature. Although this work focuses primarily on adhesively bonded joints, the final chapter extends these technologies to composite structures, such as sandwich structures, marking the initial steps toward broader application of this debond-on-demand technology.
