The curing of an epoxy prepolymer based on the diglycidyl ether of bisphenol A (DGEBA) with dicyandiamide (DDA) as the hardener and imidazole as the catalyst agent was analyzed using microdielectrometry, differential scanning calorimetry, viscosity measurements, and insolubles in THF for gel‐point detection. Interpreting dielectric data with respect to chemorheology continues to be the subject of scientific discussion. The focus of this issue is to give an industrial point of view on the collected on‐line dielectric measurements during an epoxy/fiber glass composite cure. Hence, isothermal polymerizations of DGEBA/DDA/imidazole resin were examined and dielectric properties such as ionic conductivity were related to the cure kinetics by conversion through an experimentally established equation. This mathematical model was used to predict reaction advancement of epoxy processing under nonisothermal cure conditions. This model is shown to be able to forecast both isothermal and nonisothermal cure data of unaged resin. According to these results, cure monitoring was carried out on prepregs. Whereas some deviations of the law were observed at the time of the last stage of the cure, good correlation was obtained for the reaction rate during the in‐mold process curing time.

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