Title :
Influence of uniaxial and biaxial orientation on the dielectric properties of PET
Author :
Bernes, Alain ; Chatain, D. ; Lacabanne, C. ; Lorentz, Gérard
Author_Institution :
Lab. de Phys. des Solides, CNRS, Toulouse, France
Abstract :
A comparative study of amorphous, uniaxially and biaxially oriented films was performed using thermally stimulated current (TSC) spectroscopy. The TSC peak around the glass temperature (Tg) was investigated. In amorphous polyethylene terephthalate (PET) a TSC peak was observed at 82°C, while under uniaxial orientation, it was shifted to 88°C, and under biaxial orientation, it reaches 100°C. The shift of this Tg peak under stretching indicates a stiffening of the amorphous chains. The analysis of the fine structure of these complex peaks shows the existence of compensation phenomena. For uniaxially and biaxially oriented PET this analysis reveals a lower and upper temperature component for the glass transition. This phenomenon indicates the existence of a segregated phase
Keywords :
dielectric properties of solids; polymer films; polymer structure; thermally stimulated currents; 100 degC; 82 degC; 88 degC; amorphous chains; amorphous polyethylene terephthalate; biaxial orientation; compensation phenomena; dielectric properties; glass temperature; lower temperature component; segregated phase; thermally stimulated current; uniaxial orientation; upper temperature component; Amorphous materials; Annealing; Conductivity measurement; Crystallization; Dielectrics; Glass; Polarization; Positron emission tomography; Spectroscopy; Temperature;
Conference_Titel :
Electrical Insulation, 1990., Conference Record of the 1990 IEEE International Symposium on
Conference_Location :
Toronto, Ont.
DOI :
10.1109/ELINSL.1990.109795
