Comparative thermally stimulated creep and depolarization currents study in PVC

Thermally Stimulated Creep and Depolarization Current measurements have been carried out on pure PVC. Results from β relaxation point out the same origin for mechanical and dielectric spectra and a compensation laws analysis leads to two different relaxation times distributions. Kinetic studies performed by the two techniques in the glass transition region denote a high degree of cooperativity of the involved molecular motions. Depolarization spectrum shows a high temperature peak, not formed in the mechanical one, whose evolution with the poling field allows to assign it to a non-dipolar process associated to the movement of free charge carriers.