Dianhydrides
Dianhydrides are molecules containing two acid anhydride functions. They are mainly used to synthesize polyimides and sometimes polyesters and polyamides.
Examples of dianhydrides: pyromellitic dianhydride (PMDA), 3,3’, 4,4’ - oxydiphtalic dianhydride (ODPA), 3,3’, 4,4’-benzophenone tetracarboxylic dianhydride (BTDA), 4,4’-diphtalic (hexafluoroisopropylidene) anhydride (6FDA), benzoquinonetetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride.
Read more about this topic: Acid Anhydrides