Effect of interface polarization on dielectric properties in nanocomposite compounded with epoxy and montmorillonite

Epoxy/organic-montmorillonite nanocomposites were prepared with different organic-montmorillonite and content of montmorillonite by diglycidyl ether of bisphenol A. Chemical composition of different organic-montmorillonite was analyzed by Fourier Transition Infrared(FTIR). The temperature properties of resistivity of composites were measured by Megger. The temperature dependence of composites dielectric spectrum was verified by using a Schering bridge. The results show that whether octadecyl ammonium chloride or the coupling agent KH550, they can interact with the montmorillonite both. The test results of the composite indicated that, inclusion of K-MMT and O-MMT into epoxy matrix can reduce permittivity and dissipation factor. The permittivity and dissipation factor of K-MMT/EP composites respectively reduced 5% and 35%, and those of O-MMT/EP composites respectively reduced 16% and 41%, when testing temperature is 160°C. It can be confirmed that epoxy improved by organic-montmorillonite is provided with better heat resistance property than those of pure epoxy. As for O-MMT/EP composites, the permittivity and dissipation factor of composites that contains 5wt% O-MMT is lowest. For instance, the permittivity reduced 18% and the dissipation factor reduced 42% than pure epoxy, when it is room temperature and power frequency.