Mechanical Degradation of Silicate‐Modified Epoxy Resin by Hydrothermal Aging at the Glass Transition Temperature

Epoxy resin and its composites have wide industrial applications due to their superior mechanical properties and corrosion resistance. However, their inherent toughness presents challenges at the end‐of‐life: substantial energy is consumed during the comminution for recycling. To settle this problem, the strategy of silicate modification is adopted, and corresponding mechanical properties are investigated by tensile and compression tests. Additionally, hydrothermal aging effects on PER (pure epoxy resin) and SMER (silicate‐modified epoxy resin) are investigated. Water bath and vapor environments at their glass transition temperature (80°C) are chosen as the aging methods. The results show that particle doping maintains the stiffness and yield strength but reduces the fracture compressive strain of epoxy resin, which benefits both the applications and waste disposal. After half‐month hydrothermal treatments at 80°C, the elastic modulus and yield strength of PER and SMER descend dramatically. Compared with water bath treatment, vapor environments can embrittle specimens instead of increasing their ductility. This mechanism is validated by the fracture morphology and microscopic imaging. The strategies of epoxy modification and hydrothermal aging methods in this work are instructive for the waste disposal of thermosetting resin and its composites.