Itaconic anhydride (ITA) is a biobased material that is obtained from renewable resources. It is produced from the pyrolysis of citric acid or by fermenting carbohydrates which forms itanoic acid. Itanoic acid can be dehydrated to form an anhydride. It is relatively more reactive that maleic anhydride and can be used as an alternating monomer that facilitates the introduction of polar functionalities in polymers.
Crystallise the anhydride from CHCl3/pet ether. It can be distilled under reduced pressure. Distillation at atmospheric pressure, or prolonged distillation causes rearrangement to citraconic anhydride (2-methylmaleic anhydride). If the material (as seen in the IR spectrum) contains much free acid, then heat with acetyl chloride or SOCl2, evaporate and distil at as high a vacuum as possible. The crude anhydride deposits crystals of itaconic acid on standing probably due to hydrolysis by H2O — store it in sealed ampoules under dry N2. [Skinner et al. Org Synth Coll Vol II 368 1943, IR: Nagai Bull Chem Soc Jpn 37 369 1964, Kelly & Segura J Am Chem Soc 56 2497 1934, Beilstein 17/11 V 66.]
