Single-bond dual dynamics: Temperature-gated associative and dissociative exchange of disulfides in a sustainable covalent adaptable network

Dynamic covalent chemistry provides a powerful route to sustainable polymer networks, yet achieving precise control over multiple exchange mechanisms within a single bond remains challenging. Here, we report a covalent adaptable network (CAN) based exclusively on disulfide bonds that exhibits a temperature-gated switch between associative and dissociative exchange pathways, without the need for mixed chemistries or additives. Below 365 K, the material behaves as a vitrimer via disulfide metathesis; above this threshold, it transitions to a dissociative regime governed by heterolytic S-S bond cleavage. This sharp and reversible shift demonstrates a cleanly resolved dual dynamic mode within a single bond type. The material combines excellent thermal and chemical resistance with self-healing at room temperature and full mechanical recyclability, achieving high performance alongside environmental resilience. Synthesized via a green, scalable process from a commercially available, low-cost monomer, this system advances recyclable thermosets and establishes a new model for sustainable, stimuli-responsive materials. • Disulfide-based CAN shows temperature-gated dual dynamic behavior. • Associative exchange below 365 K switches to dissociative above. • First clear separation of dynamic modes in a single bond system • Enables full recyclability and self-healing at room temperature • Sustainable synthesis from a low-cost, commercially available monomer