Dielectric properties of ethyl cellulose and ethyl-cellulose acrylic acid system

Dielectric permittivities and losses were measured above room temperature in the frequency range 10/sup 2/-10/sup 6/ Hz for undoped and acrylic acid (AA) doped ethyl cellulose (EC) films (thickness about 20 microns) with progressively increasing AA concentration. The variation of permittivity with temperature is attributed to thermal expansion in the lower temperature region to the orientation of dipolar molecules in the neighbourhood of Tg and random thermal motion of molecules above Tg. The dielectric losses exhibit one peak. Doping with acrylic acid is found to affect the magnitude and position of the loss peak. An explanation for this has been attempted on the basis of charge transfer complex formation.