Exploring Self-Repair Capabilities of ATSP Vitrimers for Crack Mitigation in Aerospace Applications

Vitrimers, although categorized as thermosetting polymers, differ from traditional ones in that their thermally induced crosslinks undergo reconfiguration through covalent bond exchanges in response to thermal stimuli. Exchangeable bonds present significant and distinctive advantages for thermoset-based aerospace composites, facilitating capabilities such as self-repair and crack arrest through molecular bridging. In this work, the self-healing behavior of four different blends of Aromatic Thermosetting Copolyester (ATSP) coatings, which are high-performance vitrimer polymers, is tested by introducing micro-scratches on the surface and healing them at higher temperatures. In three blends, the scratches are completely healed indicating complete repair. This property of the ATSP coatings can be useful in extreme conditions where micro-cracks lead to failure. The healing ability of the vitrimers is discussed in terms of their mechanical properties and morphological parameters such as branch density.