- In contrast, **thermoset plastics** (including polyurethanes, polyimides, melamine, and urea-formaldehyde) **resist softening when heated**. ([Location 1727](https://readwise.io/to_kindle?action=open&asin=B08SGC3TD3&location=1727)) --- **Tags** -- [[quotes]], [[plastics]], [[polyurethanes]], [[polymides]], [[melamine]], [[urea-formaldehyde]], [[chemistry]], **Source** -- [[202412030828 - B - How the World Really Works]]