Dielectric monitoring of curing process for some epoxide-amine thermosets

Three recently synthesized epoxy monomers were studied. All the monomers form a nematic phase in temperatures above 80 °C. This paper presents the dielectric response of pure monomers in the frequency range of 106–109 Hz as well as its changes occurring in the course of crosslinking with 4,4′-diaminodiphenylmethane used as curing agent. A relaxation process related to molecular motions is clearly visible in this frequency range for each of the monomers, though its characteristics are somewhat different in particular cases. The evolution of the relaxation process is visible in the course of curing. The dynamics of curing observed through dielectric data is compared with the results of differential scanning calorimetry measurements.