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Dielectric spectra of pure chitosan films and chitosan films with different fillers were obtained. Two relaxation processes in 200 – 500 K temperature intervals were observed: wide β - peak in the region of 290 K and  - peak in the region of 390 K. The first peak due to the presence of the polymer-bound water and/or acetic acid and disappears when filler injected into the polymer. The second peak may be associated with the activation of the nonohmic conductivity.

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Thermally stimulated depolarization currents (TSDC) in polyethylene terephthalate (Hostaphan) films of different thickness (12, 25, and 50 μm) have been investigated under different environmental conditions in the temperature range of 20–150 °C. Two peaks of TSDC spectra observed at approximately 80 and 125 °C originate from a dipolar process (α peak) and a space-charge relaxation (ρ peak), as evidenced from the variation of parameters such as electrode geometry and polarizing voltage. A numerical method (Tikhonov regularization procedure) has been employed to determine the most probable values of effective frequency factors of dipolar and space-charge relaxation in polyethylene terephthalate. An apparent influence of environmental pressure on the location of the α peak has been observed whose origin is yet to be determined.

The analysis of the thcrmallly stimulatcd short-circuit currents in a imonoelectrct with nonblocking electrodes shows that for practically relevant cases it is possible to use the drift approximation as well as the approximation of uniform space charge carriers distribution and the approximation of time distribution and the approximation of time of flight. In electroneutral dielectric (with space-charge polarization) the external short-circuilt currcnt equals to the average diffusion current in a dielectric. However, as it is shown here, the drift current in local regions of a dielectric can influence the kinetics of the thermally stimulated c!urrent and the process of charge carriers recomhination as well.Thermally stimulated shon-circuit currents (TSSCC) are one of the most efficient techniques for the investigation of electrically active defects (for example charge caniers capture centers) which are responsible for the electret state in a dielectric [1,21. The theory of thermally stimulated currents allows to obtain analytical dependencies of current versus temperature (at a given heating rate) using a number of relevant assumptions and approximations. The prcsent paper deals with the issue of possibility to use the common approximations in the TSSCC theory taking as an example a dielectric with space-charge polarization. s in aLet's consider a one-dimension model of homogeneous dielectric with one type of mobile charge carriers. The discharge current density is defined by the equation for total current which for the discussed model is a aE 8P j ( t ) = ~j )~( x , f ) + q~~( x , f )~(~,~) -q D -+ & &~--+ -where h -equilibrium conductivity of a dielectric: q, w, D and n -charge, mobil~iry, diffusion coefficient and concentration of free charge carriers correspondingly; E -high frequency dielectric permitivity defined by elastic polarization of a dielectric (that is, it doesn't take into account the input of relaxation polarization): E,, -electrical constant; E(x,t) -electric field strength inside of the diefectric; P(x,t) -module of polarization vector, generated by all types of relaxation except CH35808/96/0-7803-2695-4$04.00