A simple imide compound as a curing agent for epoxy resin. I. Synthesis and properties

A simple imide compound, 4-amino-phthalimide (APH), was synthesized as a curing agent for epoxy resin. APH was prepared from the hydration of 4-nitrophthalimide, which was prepared from the nitration of phthalimide. The chemical structure of APH was verified by IR and ¹H-NMR spectra. The thermal properties and dielectric constant (e) of a phosphorus-containing novolac epoxy resin cured by APH were determined and compared with those of epoxy resins cured by either 4,4′-diamino diphenyl methane (DDM) or 4,4′-diamino diphenyl sulfone (DDS). The results indicate that the epoxy resin cured by APH showed better thermal stability and a lower 8 than the polymer cured by either DDM or DDS. This was due to the introduction of the imide group of APH into the polymer structure.