Is epoxy resin a plastic ? For clarity when I say plastic I mean of the same ilk as all the single use plastics we (should) be trying to reduce the use of.
Yes. The IUPAC definition of a plastic (page 384 of document, page 18 of pdf file) is
- plastic - Generic term used in the case of polymeric material that may contain other substances to improve performance and/or reduce costs.
Note 1 - The use of this term instead of polymer is a source of confusion and thus is not recommended.
Note 2 - This term is used in polymer engineering for materials often compounded that can be processed by flow.
Before the epoxy sets it will flow, so it is a plastic.
As far as I am aware, the term plastic was in use long before the materials it is now associated with. It was one of the terms used to describe material states/properties: elastic, plastic and fracture.
elastic = non permanent deformation, stretches and returns to original dimensions.
plastic = permanent deformation, stretches beyond the elastic stage.
fracture = the point at which the limit of plastic deformation ends by breaking.
So it may depend on how you're using the term, but I would probably use both plastic or resin for either since they both start as resins and they "can" both have a plastic deformation stage when set/cured. Thermoplastics set, thermoset resins/plastics cure. Anyone suggesting that epoxies should not be called plastic because they're generally incompatible with thermoplastic, is false since different formulations of thermoplastics are also generally incompatible with each other.