The influence of polyetherimide on gelation and phase separation in epoxy systems

In the process of curing under thermostatic conditions, the time dependence of active and reactive components of the dielectric permittivity of epoxy amine compositions that contain a thermoplastic substance is studied in a wide range of electrical frequencies. The times of gelation and vitrification are calculated from the dielectric data and the onset of the phase separation is identified. The curing behavior established by dielectric spectroscopy is confirmed by viscometry and optical microscopy. During the phase separation, the morphology of the precipitating phase differs between samples depending on the chemical nature of the curing agent.