Bio-derived isosorbide–siloxane molecular hybrid epoxy resins for fast-curing and degradable high-performance adhesives

Cycloaliphatic epoxy resins are widely used in electronic and structural adhesive applications because of their excellent thermal stability and mechanical performance. However, conventional epoxy systems often require inorganic fillers to achieve sufficient thermomechanical performance and generally lack inherent degradability, thus raising concerns regarding end-of-life management. Here, we report an epoxy-functionalized isosorbide–siloxane molecular hybrid resin (EIS) synthesized via base-catalysed condensation of bio-derived isosorbide and an epoxy-functional alkoxysilane. The resulting oligomer preserves cycloaliphatic epoxide groups for subsequent cationic curing while incorporating hydrolytically labile silyl ether linkages within the backbone. Compared with the reference cycloaliphatic epoxy formulation, the EIS-based resin exhibits accelerated cationic curing behaviour and forms a cured hybrid network with improved thermomechanical performance and die-attach adhesion. In addition, the incorporation of alkali-labile Si–O–C silyl ether linkages enables alkaline-triggered degradation, providing a chemically addressable pathway for end-of-life disassembly. These results demonstrate that molecular-level integration of rigid bio-derived segments with an inorganic siloxane framework provides filler-free reinforcement while introducing a chemically addressable degradation pathway. This molecular hybrid design is a promising strategy for developing fast-curing, high-performance, degradable epoxy adhesives for sustainable electronic and structural applications.