Thermosetlike

Thermosetlike is a term used to describe polymeric materials that, in their crosslinked network, resemble conventional thermosets in terms of insolubility, dimensional stability, and high thermal resistance, but which can be reprocessed or recycled under certain conditions. The label is often applied to covalent adaptable networks and vitrimers, where the network includes dynamic covalent bonds that undergo bond-exchange reactions. Through these exchanges, the network can flow or rearrange at elevated temperatures without losing crosslink density, enabling reshaping, repair, or recycling while preserving much of the original chemical identity.

In practice, thermosetlike materials rely on dynamic chemistries such as transesterification, transamination, imine exchange, boronic ester exchange, or reversible Diels–Alder reactions. The key distinction from classic thermosets is the presence of a topology freezing transition temperature (Tv) above which bond exchange allows network rearrangement, while below Tv the material behaves as a solid. Availability of catalysts and the choice of exchange mechanism influence reprocessability, stiffness, Tg, and chemical resistance.

Design strategies emphasize balancing crosslink density, dynamic bond concentration, and processing conditions. Testing focuses on solubility, thermal stability, mechanical properties, and reprocessing cycles to assess durability.

Applications include recyclable coatings and adhesives, thermosetlike resins for composites, and electronic encapsulants where reuse or repair is valuable. While offering reprocessability, thermosetlike systems may exhibit different aging behavior and may require catalytic or thermal triggers, potentially adding complexity and cost.

See also: vitrimers, covalent adaptable networks, thermosets, thermoplastics.