thermoharder

A thermoharder is a type of polymer that undergoes an irreversible chemical change when heated. This process, known as curing or cross-linking, creates a rigid, infusible, and insoluble network structure. Unlike thermoplastics, which can be repeatedly melted and reshaped, thermoharders solidify permanently upon heating and do not soften significantly when reheated.

The curing process involves the formation of strong covalent bonds between polymer chains. These bonds restrict the movement of individual polymer chains, leading to a highly stable and rigid material. Common examples of thermoharders include epoxy resins, phenolic resins, polyester resins, and vulcanized rubber. These materials are widely used in applications requiring high strength, durability, and resistance to heat and chemicals, such as in adhesives, coatings, composites, and electrical insulation. The specific properties of a thermoharder depend on the type of polymer, the curing agent used, and the conditions of the curing process.