Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Physicochemical synergy between ETBN and TDE-85 enables epoxy resin to overcome the usual trade-off between toughness and insulation. The dual-modified system builds a balanced network that raises flexural strength and modulus by 37% and 35%, while boosting breakdown strength by 63%, pointing to more reliable high-voltage cable insulation.

ABSTRACT
Epoxy resins are widely used in high-voltage power cable systems because of their mechanical and electrical insulation properties. However, the cable terminations operate under complex service conditions, and conventional epoxy resins used as insulating housings are prone to embrittlement. Consequently, a major challenge in epoxy resin development is enhancing their toughness without compromising the outstanding electrical insulation performance of E51 resin. This study aims to synergistically toughen E51 resin through a combined physical–chemical approach using epoxy-terminated acrylonitrile butadiene liquid rubber (ETBN) and 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester (TDE-85). The effects of this modification on mechanical properties, dielectric performance, and insulation performance are systematically investigated. The results show that, compared with the unmodified resin, the formulation containing 15 phr ETBN and 15 phr TDE-85 increases flexural strength by 37% and modulus by 35%, while raising the breakdown strength by 63%. This work provides an effective modification strategy for expanding the application of epoxy resins in enhancing the performance stability of high-voltage power cable systems.