Dianhydrides are a type of anhydride, a general class of fine chemical intermediate formed by the removal of water from an organic acid. The simplest example includes two acyl groups bound by a common oxygen molecule. A “dianhydride” is a molecule that contains two anhydride groups.

Cyclic dianhydrides are popular curatives in epoxies, polyimides, polyesters and other resin systems. The value of dianhydrides is quite universal across a myriad of applications:

Improved retention of physical, mechanical and electrical properties at elevated temperatures for extended periods of time

Dianhydrides serve as thermal curatives for epoxy resins, creating a highly-crosslinked three-dimensional polymer network. These polymers find widespread use in the coating and protection of electronic components and pipelines as well as in producing composites and adhesives.

Polyimides are synthesized using dianhydrides as a co-monomer with diamines. Composites, fibers, films, and foams are but a few of the many applications where polyimides are called upon to provide heat resistance, electrical resistance and dimensional stability under aggressive conditions.

Dianhydrides can also be used to combine different chemistries into new hybrid resin systems.