What describes thermosetting adhesives once cured?

Thermosetting adhesives are designed to undergo a chemical change when cured, resulting in a hardened and inflexible structure. Once these adhesives are cured, they cannot be re-softened by heating. This process is irreversible; the heat causes a polymerization reaction that forms cross-links between the molecular chains in the adhesive. As a result, the cured adhesive retains its shape and strength under heat and does not flow or become soft again, distinguishing it from thermoplastic adhesives, which can be re-melted and reshaped.

This characteristic of thermosetting adhesives makes them particularly suitable for applications that require durable and stable bonds under various environmental conditions, as they provide long-lasting performance once fully cured.