CoachA thermoplastic softens each time it is heated and hardens again when it cools: it can be melted and moulded again and again (PET, polyethylene, PVC, polypropylene, polystyrene). A thermoset sets for good when it is first heated and moulded: heated again, it does not soften but chars (Bakelite, the resins of glues and of boat hulls).
Chemistry · Glossary
What is Thermoplastic and thermoset?
Also known as: thermoplastic · thermoset