Thermally stimulated depolarization currents study of structural features of polymers

Molecular mobility at the glass-transition region of the block styrene-butadiene-styrene (SBS) copolymers has been investigated by means of thermally stimulated depolarization currents (TSDC). The TSDC maxima, /spl alpha//sub 1/, have been attributed to the glass transition temperature of the butadiene phase T/sub /spl alpha//, B, according to differential thermal analysis data. The main features of the TSDC spectra are: 1) peak amplitude is a linear function of external field, 2) peak shape and its temperature position depend on the polarization temperature T/sub p/. Such results are meaningful for a dipole relaxation time distribution. The dipole distribution function of relaxation times has been calculated from the TSDC curve.