The electrical properties of cellulose acetate and methyl cellulose fr
ee of inorganic impurities and contaminated with water soluble inorgan
ic salts were measured in the frequency range 0.05-100 ke/s at 283-333
K temperatures. The results obtained show that the relation represent
ing the variation with temperature of the real part of the dielectric
permittivity with the samples examined exhibits a second order transit
ion at about 303 K, and that, when these samples are contaminated with
NaCl salt, such a relation takes plate exponentially, particularly at
very low frequencies, and a real dielectric dispersion and a loss pea
k were found. The data have been discussed in view of the interfacial
polarization that occurs in the case of inhomogeneous dielectric conta
minated with inorganic impurities.