Hydrogen bond-driven rigid filling strategy: Regulation of epoxy resin network structure and properties by anchored groups

The free volume within an epoxy resin curing system is recognized as a critical determinant of its modulus. This study introduces a "hydrogen bond-driven rigid filling effect," achieved by incorporating rigid anchored groups of varying sizes into the epoxy resin system. These groups enhance network densification through conformational transitions and Π-Π stacking interactions, effectively reducing free volume while improving the glass transition temperature (T_g), mechanical properties, and thermal stability of the cured system. Notably, smaller benzene ring groups within the RAE complex system demonstrate greater efficacy in filling network voids. This study elucidates the role of rigid filling in epoxy resin networks, highlighting the enhancement of hydrogen bonding sites within attached groups. These findings present a novel approach for designing high-performance epoxy resin materials.