Improved cryogenic mechanical properties and liquid oxygen compatibility of MoS2/Epoxy nanocomposites via KH560-Functionalization

The 0.2 phr KH560-MoS₂/epoxy nanocomposite exhibits optimal mechanical properties at both RT and 90 K. • Compared with neat epoxy, the 0.2 phr KH560-MoS 2 /EP system exhibits significantly improved liquid oxygen compatibility. • Combining 15 phr TAD with 0.2 phr KH560-MoS₂ yields high char residue and full liquid oxygen compatibility. Carbon fiber-reinforced epoxy composites exhibit significant lightweight potential for liquid oxygen (LOX) cryogenic tank applications. Nevertheless, their practical deployment is heavily constrained by the dual challenges of extreme cryogenic environment (90 K) and inherent incompatibility with liquid oxygen. Epoxy resins, when employed as matrices, cannot address the two critical challenges and hence need to be modified. In this study, epoxy resin is modified by grafting two-dimensional molybdenum disulfide (MoS 2 ) nanosheets with KH560 silane coupling agent. Mechanical properties of the modified epoxy system are systematically evaluated at room temperature (RT) and cryogenic temperature (90 K). The results show that at an optimal content of 0.2 phr, the incorporation of KH560-MoS 2 simultaneously enhances the mechanical properties at both RT and 90 K. Moreover, the liquid oxygen compatibility of the 0.2 phr KH560-MoS 2 /EP system is notably improved, and the epoxy nanocomposite further modified with 15 phr TAD and 0.2 phr KH560-MoS 2 can successfully pass the liquid oxygen compatibility test. These findings demonstrate that the proposed epoxy nanocomposite system exhibits enhanced mechanical properties and improved LOX compatibility, highlighting its potential as a matrix candidate for CFRP composites intended for cryogenic LOX tank applications.