PYROMELLITIC DIANHYDRIDE (PMDA) is the main material for producing heat resistant PI engineering plastics and insulating films. Pyromellitic Dianhydride (PMDA) CAS NO.89-32-7FormulaC6H2(C2O3)2Mol wt.218.12ToxicityOral, rat LD50: 2250 mg/kgSynonymsPMDA;1,2,4,5-BenzenetetracarboxylicDianhydride;1,2,3,5-BenzenetetracarboxylicAnhydride;1H,3H-Benzo[1,2-c:4,5-c']difuran- 1,3,5,7-tetrone; ...