Frequency dependence of the complex conductivity of thin polymer films

A method to experimentally determine the components of complex thermal conductivity for thin polymer films has been developed. It is based on measuring the temperatures of both sides of a film in which a periodic temperature wave is excited. Formulas have been derived that relate the measured temperatures to the thermal conductivity components. Using this method, the frequency dependences of the complex conductivity for cellulose (150 $\mu$m thick), fluoroplastic (600 $\mu$m), and polypropylene (600 $\mu$m) films have been obtained in the frequency range of 0.01 – 0.25 Hz at 293 K.