Dielectric Relaxation Behavior of Montmorillonite/Epoxy Resin Nanocomposites
Abstract
Based on the research status of polymer matrix nanocomposite dielectrics, this study investigates the relationship between the interfacial structure of nanocomposites and their dielectric relaxation, polarization, and loss characteristics. Bisphenol-A epoxy resin (ER), commonly used as the primary insulation material in electrical equipment, served as the polymer matrix. A layered-silicate montmorillonite (MMT) served as the nanodispersed phase. MMT/ER nanocomposites were prepared via a melt-blending method. First, the formation mechanism of the nanocomposite interface was analyzed. In the composite system, electrostatic attraction occurs between the electronegative MMT layers and positively polarized centers of the ER polar dipoles, forming an two-phase interaction interface. Second, the effects of temperature and degree of resin cross-linking on the interface structure were analyzed. The nanocomposite interface morphology changed with increasing MMT content, which also influenced the dielectric polarization and loss characteristics. Finally, dielectric spectroscopy was performed on the MMT/ER nanocomposites to investigate the effect of the interface on their dielectric relaxation behavior under different MMT contents and frequencies.