Effect of Na+ on Molecular Relaxation of Epoxy/Alumina Resin Composites

Epoxy resin is an insulating material widely used in high-voltage electrical equipment, and Na
⁺
is one of the main impurity ions in epoxy resin. In this research, we added different mass fraction Na
⁺
into epoxy/alumina composites. After that, we measured the gel time, glass transition temperature and broadband dielectric spectrum. Besides, we used H-N function to fit the data of dielectric spectrum,used VFT function to calculate the activation energy of macromolecular chains. The gel time data showed that Na
⁺
can promote the gelation of epoxy composite castables. The glass transition temperature proved that Na
⁺
can promote crosslinking. The calculation results of dielectric fitting showed that Na
⁺
can increase the activation energy of macromolecular chains and increases the intensity of ion ionization. This research reveal the effect of Na
⁺
on molecular relaxation in epoxy composites and provide reference for the control of Na
⁺
content in epoxy composites.