Manifestation of trapping border states in 1,4-cis-polybutadiene/SiC nanocomposite films

As a subject of study, we have chosen 1,4-cis-polybutadiene polymer containing 96% of cis and 4% of trans form, 1,4-cis-polybutadiene doped with single-crystalline silicon carbide (SiC) in weight ratio 5%. An influence of SiC crystallites on the dc-electric properties of 1,4-cis-polybutadiene versus temperature and intensity of electric fields was investigated. A set of the TSDC spectra was obtained under different annealing rates (β=0.05 to 0.25 K s−1) within temperature range from 15 to 325 K. In case of pure 1,4-cis-polybutadiene polymer an area of the glass transition (Tg), a high-elastic transition and also a signal related to process of melting of crystallites (Tk) were studied. The values of the phase-transition energy were calculated using different methods often applied to describe the thermal-stimulated currents (TSC). In case of 1,4-cis-polybutadiene doped with SiC, the current signal related to the glass transition (Tg) was observed but the signal related to a process of crystalline melting (Tk) was absent [R. H. Bube, Photoconductivity of Solids, Wiley and Sons, New York, 1960]. A brief description of theoretical approaches was helpful in determining the trapping levels of nanoparticles incorporated into the polymer matrix using the technique of thermally stimulated depolarization currents (TSDC) is presented.