Thermosetting polymer
A thermosetting polymer (or plastic), also known as a thermoset, is a prepolymer material which cures irreversibly. The cure may be induced by heat, generally above 200 °C (392 °F), through a chemical reaction, or suitable irradiation.
Thermoset materials are usually liquid or malleable prior to curing and designed to be molded into their end form, or used as adhesives. Others are solids like that of the molding compound used in semiconductors and integrated circuits (IC). Once hardened a thermoset resin cannot be reheated and melted to be shaped differently.
Thermosetting resin may be contrasted with thermoplastic polymers which are commonly produced in pellets and shaped into their final product form by melting and pressing or injection molding.
Definition
IUPAC defines a thermosetting resin as a prepolymer in a soft solid or viscous state that changes irreversibly into an infusible, insoluble polymer network by curing. Curing can be induced by the action of heat, suitable radiation, or both. There are various kinds of thermosetting plastics. A cured thermosetting resin is called a thermoset.
