Thermosetting polymers

Thermosetting polymers undergo a chemical change and once formed or set, cannot be reformed. Thermosets are resistant to higher temperatures but tent to burn when heated rather than melt. They are harder, more brittle and provide good insulation and chemical resistance.

Polyester resin (PR)

Good electrical insulator, hard, but becomes tough when mixed with glass strands to form glass reinforced plastic (GRP)

Used for encapsulation, boat hills as GRP.

Urea formaldehyde (UF)

high tensile strength, heat resistant, good electrical insulator, hard, brittle, easily injection moulded.

Used for adhesives for bonding particle boards, decorative laminates, electrical casings (power plugs).

Epoxy resin (ER)

Good strength to weight ratio, good electrical conductor, heart resistant.

Used for bonding waterproof coatings, electronic circuit boards.

Phenol formaldehyde (PF)

Heat resistant and a good electrical insulator.

Used for heat resistant handles, electrical components, and snooker balls.

Melamine formaldehyde (MF)

Lightweight, hard but brittle.

Used for worktops, surfaces, some kitchenware.

Thermoforming

Plastics are more flexible and have looser polymer chains that break when heated.

Thermosetting

Plastics have rigid cross-linked polymer chains that set when heated and cannot be reformed.