Research on the Toughening and Performance of Epoxy Resin for Electrical Packaging

ABSTRACT With the advancements in power transmission technology, the construction environments for high‐voltage (HV) and ultrahigh‐voltage (UHV) transmission lines have become increasingly sophisticated, placing higher demands on the toughness of insulating encapsulating materials for electrical equipment. Although the inherent rigidity of epoxy resin (EP) contributes to its exceptional mechanical and electrical insulation performance, its inherent brittleness and poor impact resistance limit its application in the encapsulation of electrical devices operating under demanding conditions. To address this issue, this research selected two toughening agents with different toughening mechanisms to modify the epoxy resin formulation system for dry‐type reactors. We aimed to verify how these toughening agents are based on their distinct mechanisms and highlight different toughening effects on the EP matrix. Consequently, a novel EP formulation system was developed, achieving significantly enhanced mechanical properties while maintaining uncompromised insulation performance.