Molecular dynamics study on the crosslinking reactions and performance characteristics of epoxy resins

A systematic approach combining molecular dynamics (MD) simulations and density functional theory (DFT) calculations was developed to predict and optimize the performance of epoxy resins. The effects of side-chain modifications (glycidyl amine, glycidyl ether, and glycidyl alkyl) on TDE-85 epoxy resin systems were quantitatively evaluated, focusing on glass transition temperature (Tg), mechanical properties, and free volume. MD simulations revealed that glycidyl amine-modified TDE-85 exhibited the highest Tg (554.69 K) and superior mechanical performance, attributed to restricted molecular mobility and reduced free volume. Crosslinking mechanisms between epoxy resins and amine-based curing agents were further investigated, demonstrating that side-chain structures critically influence reaction efficiency and final network properties. The interaction dynamics of active hydrogen with epoxy groups were analyzed to elucidate correlations between crosslinking density and macroscopic performance. Optimizing side-chain structures significantly enhanced thermal stability and mechanical strength, with glycidyl amine modifications to TDE-85 showing the most pronounced improvements. This work provides molecular-level insights into structure-property relationships in epoxy resins, proposing a targeted strategy for side-chain engineering to achieve high-performance materials. The methodology establishes a theoretical framework for rational design of epoxy systems and offers transferable principles for performance prediction in analogous polymer materials.