Epoxy resins with high thermal stability, good mechanical properties and liquid oxygen compatibility are primary candidates in large cryogenic engineering projects, particularly for cryotank applications to avoid catastrophic accidents. Herein, an experimental characterization and molecular dynamics modeling are conducted for the thermal stability, mechanical properties and liquid oxygen compatibility of multiple epoxy systems. The multiple epoxy systems are synthesized to achieve a comprehensive evaluation of their thermal stability, room-temperature and cryogenic mechanical properties as well as liquid oxygen compatibility. Concretely speaking, the anti-oxidation properties of the degradation are investigated by thermogravimetric analysis (TGA) and the glass transition temperature (Tg) is measured by the differential scanning calorimetry (DSC). The tensile test and fracture toughness test under room-temperature/cryogenic conditions (90 K) are chosen for determining their mechanical performances. Moreover, limited oxygen index measurements and liquid oxygen impact tests are utilized to characterize the flame retardancy and liquid oxygen compatibility, respectively. In parallel, molecular dynamics models are established to construct the high cross-linking structures and predict thermomechanical properties, which helps reveal the relationship between the molecular structures and macroscopic properties. Finally, the synergistic effects of organic/inorganic flame retardants and polyurethane toughener are proven to be effective to balance the liquid oxygen compatibility and mechanical properties. The valuable and extensive evaluation data in this work could be beneficial to the epoxy resin system design for cryotank applications.

具有高热稳定性，良好的机械性能和液氧相容性的环氧树脂是大型低温工程项目中的主要候选产品，尤其是用于低温罐应用以避免灾难性事故。本文中，针对多种环氧体系的热稳定性，机械性能和液氧相容性进行了实验表征和分子动力学建模。合成了多种环氧体系，以全面评估其热稳定性，室温和低温机械性能以及液氧相容性。具体而言，通过热重分析（TGA）研究降解的抗氧化性能，并且通过差示扫描量热法（DSC）测量玻璃化转变温度（Tg）。选择室温/低温条件下（90 K）的拉伸试验和断裂韧性试验来确定其机械性能。此外，有限的氧指数测量和液氧冲击测试分别用于表征阻燃性和液氧相容性。同时，建立了分子动力学模型以构建高交联结构并预测热机械性质，这有助于揭示分子结构与宏观性质之间的关系。最后，有机/无机阻燃剂和​​聚氨酯增韧剂的协同作用被证明有效地平衡了液氧相容性和机械性能。