Thermally stimulated depolarization current studies of poly(ethylene oxide) and poly(ethylene oxide) complexed with potassium thiocyanate

Abstract

A digitally controlled thermally stimulated depolarization current facility is described and measurements on poly(ethylene oxide) (PEO) and PEO complexed with potassium thiocyanate (KSCN) are reported. The results complement and extend previous electrical relaxation studies on these materials. In particular, in PEO the presence of a relaxation previously labeled αc is confirmed. The relaxation is assigned to defects in the crystalline phase. In addition, the γ relaxation region is shown to consist of at least two relaxations. Further, a high-temperature family of peaks is obtained which are associated with space charge. For KSCN-complexed PEO three low-temperature relaxations are observed in the γ relaxation region. The relationship between these relaxations and previously reported dielectric relaxation results is established and possible origins of the relaxations are discussed. Finally, differential scanning calorimetry studies were carried out on all of the materials.