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In materials science, a thermosetting polymer, often called a thermoset, is a polymer that is obtained by irreversibly hardening ("curing") a soft solid or viscous liquid prepolymer . [1] Curing is induced by heat or suitable radiation and may be promoted by high pressure or mixing with a catalyst .
Thermoset plastics and thermoplastics together constitute the two major components of synthetic plastics. Thermosetting plastics are divided into two types: formaldehyde cross-linking type and other cross-linking type. Thermosets includes phenolic resins, polyesters and epoxy resins, all of which are used widely in composite materials when ...
A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. [ 1 ] [ 2 ] Most thermoplastics have a high molecular weight .
A thermoset polymer matrix is a synthetic polymer reinforcement where polymers act as binder or matrix to secure in place incorporated particulates, fibres or other reinforcements. They were first developed for structural applications, [ 1 ] such as glass-reinforced plastic radar domes on aircraft and graphite - epoxy payload bay doors on the ...
A surfboard made of vitrimers could be brought into a new shape, scratches on a car body could be cured and cross-linked plastic or synthetic rubber items could be welded. Vitrimers, which are prepared from metathesis of dioxaborolanes with different commercially available polymers, can have both good processibility and outstanding performance ...
Thermoset resins require addition of a curing agent or hardener and impregnation onto a reinforcing material, followed by a curing step to produce a cured or finished part. Once cured, the part cannot be changed or reformed, except for finishing.
Thermosetting plastics or silicone rubber gels are often used, though epoxy resins are also very common. When epoxy resins are used, low chloride grades are usually specified. [ 1 ] Many sites recommend using a potting product to protect sensitive electronic components from impact, vibration, and loose wires.
Polyester resins are thermosetting and, as with other resins, cure exothermically. The use of excessive initiator especially with a catalyst present can, therefore, cause charring or even ignition during the curing process. Excessive catalyst may also cause the product to fracture or form a rubbery material.