Atomic Oxygen Resistance Vitrimers with High Strength, Recyclability, and Thermal Stability

Vitrimers are a generation of spacecraft materials. However, how to improve the atomic oxygen (AO) resistance of vitrimers remains unexplored although it is critical for extending the lifetime of spacecraft at a low earth orbit. Herein, we fabricate a series of AO resistance epoxy vitrimers with high mechanical properties, recyclability, and thermal stability using glutaric acid to cross-link the mixture of diglycidyl ether of bisphenol F (DGEBF) and polyhedral oligomeric silsesquioxane (POSS) functionalized with epoxy groups. The rigid POSS structure not only imparts the epoxy vitrimers with high mechanical properties (up to 94.4 MPa) and thermal stability (decomposition temperature > 300 °C) but also endows the epoxy vitrimers with excellent AO resistance due to the formation of the SiO₂ layer on the surface after AO exposure. Moreover, the reversible ester bonds allow the epoxy vitrimers to be recycled and reprocessed. Therefore, this class of vitrimers hold great promise for application in spacecraft.