Rezumat
In present work the features of the dependence of radiothermoluminescense (RTL), charge stabiliza- tion, change of the temperature of structural γ-, α- and β- transition on the degree of filling of low density polyethylene (LDPE) by the RTL and thermo stimulated current (TSC) methods are investigated. The RTL curve for LDPE γ - irradiated at 77 K consist three peaks at 130, 173 and 228 K (γ-, α- and β-relaxation).The low temperature peaks (γ- and α-peaks ) of RTL for LDPE results from recombination of trapped electrons with radiolysis product (i.e.radicals) and β- peak with a luminescence centre after tunneling through a potential barrier. After modification of LDPE by introduction of SA (special additive) up to 2 wt% the RTL γ- and α-peaks shifts to lower temperatures, while the β-peak shifts to higher temperatures. TSC spectra for LDPE show two peaks (negative peak at 303 K and positive peak at 418 K) which decreases in intensity and moves toward higher temperatures as the filling degree increases. The peak qt 418 K is due to the release of trapped charges from the crystalline regions on melting.