A thermoset is a kind of polymer (that's plastic to you, folks) that forms a threedimensional network of polymer chains during polymerization. Unlike thermoplasts and elastomers (rubbers), thermosets do not melt or soften upon heating, but rather burn and/or decompose.
Thermosets (mostly polyester) are often used in combination with glass fibres, to make things like boats and airplane wings. This combination of fibre and polymer is almost as strong as steel, but much lighter.
Y'know, if you log in, you can write something here, or contact authors directly on the site. Create a New User if you don't already have an account.