Thermosetting Plastics

Definition - What does Thermosetting Plastics mean?

Thermosetting Plastics, also known as thermosetting resins, are rigid polymeric materials that are resistant to higher temperatures than ordinary thermoplastics. They are petrochemical materials that irreversibly cure. The cure may be brought on by heat, generally above 392°F (200°C), chemical reaction or suitable irradiation. It is used as adhesives as well as in semiconductors and integrated circuits. The International Union of Pure and Applied Chemistry (IUPAC) defines a thermosetting plastics as petrochemicals in an indulgent solid or viscous state that changes irreversibly into an infusible, insoluble polymer network by curing.

Petropedia explains Thermosetting Plastics

Thermosetting plastics are normally made up of lines of polymers which are highly cross-linked. The heavily cross-linked structure produced by chemical bonds in thermoset materials is directly responsible for the high mechanical and physical strength compared with thermoplastics or elastomers. However, it provides poor elasticity or elongation of the material—once hardened, a thermoset resin cannot be reheated and melted to be shaped differently. The cross-linking process eliminates the risk of the product remelting when heat is applied, making thermosets ideal for high-heat applications such as electronics and appliances. Since their shape is permanent, they tend not to be recyclable as a source for newly made plastic.

Common thermosetting plastics or resins include: