Research on Thermal Aging Properties of Modified E-51 Epoxy Resin for Cryogenic Application

E-51 epoxy resin with medium viscosity can be used to. fabricate mechanical or insulating structural components. However, because of its brittleness, the unmodified E-51 epoxy resin system can’t absorb significant internal stress at cryogenic temperature. As a result, a modified E-51 epoxy resin system for cryogenic application was developed to investigate the thermal aging properties, which aims at understanding the impact of heating temperature and heating time on the evolution of micro-structure, thermo stability, and mechanical properties. Testing results show that the modified E-51 epoxy resin system has a stable micro-structure after undergoing 50 thermal cycling and 50 thermal cycling while heating at 105℃ with a duration of 120 hours. However, the mechanical tensile strength of the modified E-51 epoxy resin system undergoes a decline of approximately 13.63% when the heating duration increases to 240 hours. Moreover, heating the modified E-51 epoxy resin system for 480 hours can lead to significant changes in the micro-structure, which ultimately affects the mechanical tensile testing results. Therefore, to achieve high performance, achieving micro homogeneity and modification of the E-51 epoxy resin system are critical.