The demand for lightweight carbon fibre-reinforced polymer matrix composites (CFRPs), which typically have an epoxy resin (EP) matrix, have been increasing in cryogenic fields. The mechanical properties of CFRPs depend largely on the mechanical properties of their EP matrix, particularly in cryogenic environments. To date, however, no commercially available EP can comprehensively fulfil the demands. In this study, biscitraconimide resin (BCI) was introduced to enhance the mechanical properties of EP. Results indicated that cryogenic tensile strength, bending strength, impact strength and fracture toughness (K_IC) were enhanced for the modified epoxy system at appropriate BCI contents. The tensile strength (144.57 MPa) of EP increased by 67.6%, and its bending strength (229.53 MPa) increased by 94.9% at 77 K. Impact strength (41.16 kJ·m⁻²) was improved by 195.7% and K_IC (2.72 MPa·m^1/2) increased by 65.9% at 77 K compared with that of pure EP. The results were properly explained via scanning electron microscopy observation, and the mechanism of the improved mechanical properties was analysed in detail.

在低温领域，对通常具有环氧树脂 (EP) 基体的轻质碳纤维增强聚合物基复合材料 (CFRP) 的需求一直在增加。CFRP 的机械性能很大程度上取决于其 EP 基体的机械性能，尤其是在低温环境中。然而，迄今为止，还没有市售的EP能够全面满足需求。在本研究中，引入了双西曲康酰亚胺树脂 (BCI) 以增强 EP 的机械性能。结果表明，低温抗拉强度、弯曲强度、冲击强度和断裂韧性（K _IC) 在适当的 BCI 含量下对改性环氧树脂体系进行了增强。EP的抗拉强度（144.57 MPa）在77 K时提高了67.6%，弯曲强度（229.53 MPa）提高了94.9%。冲击强度（41.16 kJ·m ^-2）提高了195.7%，K _IC（2.72 MPa·m ^1/2 )在77 K时比纯EP提高了65.9%。通过扫描电子显微镜观察对结果进行了适当的解释，并详细分析了机械性能改善的机理。