Synergistic enhancement of interfacial properties in epoxy resin at extreme temperatures through multi-scale interactions between CuO NRs and polysiloxane

Toughening of epoxy resin (EP) is a common topic in the research of high-performance matrix for advanced composite materials. When the material is at extreme temperatures, the toughening requirements of EP will become more prominent. To this end, we designed a multi-scale interface to improve the strength and toughness of an EP at extreme temperatures simultaneously. A multi-scale interface layer was fabricated within the EP system using CuO nanorods (NRs) and epoxy-based cage-type polysiloxane (EP-POSS) as the toughening phase. By changing the content of CuO NRs and EP-POSS, regulating the multi-scale interface structure between the two, thereby further regulating the mechanical properties of the system. When the relative contents of the CuO NRs and EP-POSS were 1:1, the mechanical properties of EP/NP-CuO were optimised at room temperature(RT) and 77 K. The tensile strength increased by 75.9 % and 97.3 %, respectively, compared to the pure EP. The fracture toughnesses increased by 83.1 % and 58.9 %, respectively, compared to the pure EP. The improvement in mechanical performance is mainly attributed to the multi-scale interface structure between NP-CuO and EP, which effectively consumes the energy and stress required during deformation.