Study on Epoxy Resin Curing Process Based on Frequency Dielectric Spectroscopy

Evaluation of epoxy cure is an important work because the final mechanical and electrical characteristics will depend upon how the curing process was done. Dielectric analysis (DEA) is one method to monitor the curing of the epoxy. Some studies on this method can already be found in literature. However, these studies do not provide a detailed analysis of the dielectric properties of the epoxy entire curing process. As a new field evaluation method for insulation condition, the frequency domain dielectric spectroscopy (FDS) has been paid more and more attention. The purpose of this paper is to analyze the dielectric properties of epoxy curing process by frequency domain dielectric spectroscopy. An experimental platform was set up to measure the epoxy curing by using dielectric response analyzer. Epoxy samples with different curing degree were prepared by changing curing time (curing degree measured by DSC). The experimental results show that at the same frequency, as the degree of curing increases, the dielectric loss factor and dielectric constant first increase, then decrease, and finally remain unchanged. The frequency domain dielectric spectroscopy has the potential to detect the degree of epoxy.