Research progress on high-performance low-temperature epoxy resins

Epoxy resins have gained widespread application in composite materials, coatings, adhesives, and related fields owing to their exceptional mechanical properties, high chemical stability, strong adhesion, and excellent electrical insulation. Specifically, low-temperature-resistant epoxy resin is defined as a variant capable of maintaining favorable mechanical performance at temperature as low as −40℃ or below, while demonstrating long-term stability in low-temperature environments. Such resins hold particular significance for low-temperature epoxy adhesives and composites. However, conventional epoxy resins often exhibit drawbacks including increased brittleness of cured products and susceptibility to interface delamination under low-temperature conditions. These limitations can be addressed through low-temperature reinforcement and toughening modification techniques to achieve epoxy resins with enhanced mechanical properties in cold environments. This paper systematically reviews recent advances in high-performance, low-temperature epoxy resins through three primary modification approaches: covalent cross-linking modification, and covalent-non-covalent co-cross-linking modification, and covalent-non-covalent co-cross-linking modification. The discussion focuses on the fundamental principles underlying these modification and provides comparative analysis of mechanical performance before and after treatment. Finally, it looks forward to the future of epoxy resins used in low-temperature environments.