Adhesives with Debonding-On-Demand Capability: Leveraging Responsive Microcapsules for Mechanically-Induced Debonding

Abstract

Temporary adhesives capable of forming strong yet easily reversible bonds are garnering significant interest as sustainable materials that facilitate the recycling and recovery of high-value components. Herein is presented a comprehensive design and parameterization framework for developing effective temporary adhesives with mechanically induced debonding-on-demand capabilities. This framework is achieved by incorporating hexyl acetate-filled microcapsules into commercial polyvinyl acetate adhesives, creating a responsive adhesive composite. Under controlled compression, these microcapsules rupture precisely, releasing their contents to induce sufficient adhesive plasticization to enable effortless debonding. Our results indicate that while the inclusion of microcapsules affects adhesion strength and toughness, the overall mechanical performance remains stable across different concentrations. Thermal tests highlight a 50 wt.% microcapsule concentration as optimal for enhanced plasticization, while compression tests show that an applied force of 5 kN achieves maximum capsule rupture without compromising substrate integrity. Ultimately, specimens bonded with the responsive composite under compression exhibit a striking 1200% increase in creep rates compared to those bonded with the neat adhesive, allowing for effective debonding-on-demand—an outcome unattainable with the neat adhesive. This simple and highly versatile approach lays the groundwork for advancing the development of more sustainable and functional adhesive materials.