Analyses of various insulating polymers by broadband dielectric spectroscopy

Nowadays, trials to use even higher frequencies are pursued to realize high-speed wireless communications. In order to respond to such a trend, dielectric properties of insulating polymers at high frequencies have to be clarified, although the importance of clarifying low-frequency properties is still very high, especially for use as high voltage insulators. In this regard, complex permittivity spectra in an ultrawide frequency range were obtained for various insulating polymers. These spectra are important, because they can be a valuable database that provide important information on dielectric characteristics. Furthermore, by analyzing the temperature dependence of permittivity in a relatively low frequency range, thermal expansion coefficients of polymers were estimated.