Science, Tech, Math › Science Thermosetting Plastic Definition Print Epoxy resin is an example of a thermosetting plastic. chonticha wat, Getty Images Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Learn about our Editorial Process Updated on September 29, 2022 A thermosetting plastic is a polymer that irreversibly becomes rigid when heated. Such a material is also known as a thermoset or thermosetting polymer. Initially, the polymer is a liquid or soft solid. Heat provides energy for chemical reactions that increase the cross-linking between polymer chains, curing the plastic. The rate of curing may be increased in many cases by increasing pressure or by adding a catalyst. Examples Read More Plastic Definition and Examples in Chemistry By Anne Marie Helmenstine, Ph.D. Many common plastics are thermosets. They include: Vulcanized rubberFiberglass (a fiber-reinforced polymer composite)Polyester resinPolyurethaneMelamineBakeliteSilicone resinEpoxy resin Sources Ellis, B. (ed.) (1993). Chemistry and Technology of Epoxy Resins. Springer Netherlands. ISBN 978-94-010-5302-0 IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). "Thermosetting Polymer". doi:10.1351/goldbook.TT07168 Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "Thermosetting Plastic Definition." ThoughtCo, Sep. 29, 2022, thoughtco.com/definition-of-thermosetting-plastic-605734. Helmenstine, Anne Marie, Ph.D. (2022, September 29). Thermosetting Plastic Definition. Retrieved from https://www.thoughtco.com/definition-of-thermosetting-plastic-605734 Helmenstine, Anne Marie, Ph.D. "Thermosetting Plastic Definition." ThoughtCo. https://www.thoughtco.com/definition-of-thermosetting-plastic-605734 (accessed April 20, 2024). copy citation