Reconciling Ultrahigh-Temperature Capability and Chemical Degradation in Bismaleimide Diphenyldisulfide-Based Polymers and Composites

Despite their widespread application in automotive, maritime, and aerospace industries, conventional thermosets and their composites suffer from nonrecyclability. Current recyclable covalent adaptable networks offer a solution but are limited by poor heat resistance. Herein, we report a diphenyldisulfide-based polymer (BMS-DB) that overcomes this limitation. The BMS-DB polymers deliver an ultrahigh Tg of ∼275 °C (high storage modulus (E') of ∼410 MPa at 325 °C), robust mechanical properties, and rapid degradability. As a matrix for carbon fiber composites, it enables an unprecedented Tg of ∼305 °C and nondestructive recycling. This combination of ultrahigh-temperature capability and closed-loop recyclability makes these materials ideal candidates for severe-service environments such as aerospace.