TY  - JOUR
A1  - Gulyakova, Anna A.
A1  - Gorokhovatsky, Yuri A.
A1  - frübing, Peter
A1  - Gerhard, Reimund
T1  - Relaxation Processes Determining the Electret Stability of High-Impact Polystyrene/Titanium-Dioxide Composite Films
JF  - IEEE transactions on dielectrics and electrical insulation
N2  - The influence of relaxation processes on the thermal electret stability of high-impact polystyrene (HIPS) free-standing films filled with titanium dioxide (TiO2) of the rutile modification are investigated by means of a combination of dielectric methods (dielectric relaxation spectroscopy (DRS), thermally stimulated depolarization current (TSDC) and thermally stimulated surface-potential decay (TSSPD)), supplemented by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Films with 2, 4, 6 and 8 vol.% TiO2 are compared to each other and to non-filled samples. Filling HIPS with up to 8 vol.% of TiO2 enhances the elastic modulus below the glass transition and increases the thermal electret stability above the glass transition without significantly increasing the DC conductivity. The improvement of the electret stability is caused by the build-up of an interface polarization which decays only gradually if the glass transition is exceeded. Two kinds of Arrhenius processes are considered in order to explain the decay of the composite-polymer electrets: (1) charge release from chemical traps located at the phenyl rings of the polymer chain with an activation energy of E-a = 1.1 eV after passing the glass transition at about 100 degrees C and (2) charge release from traps formed by the TiO2 particles with E-a = 2.4 eV at temperatures above 130 degrees C. Finally, the activation energies are discussed with respect to their significance.
KW  - High-impact polystyrene
KW  - titanium dioxide
KW  - electret stability
KW  - dielectric relaxation
Y1  - 2017
U6  - https://doi.org/10.1109/TDEI.2017.006587
SN  - 1070-9878
SN  - 1558-4135
VL  - 24
SP  - 2541
EP  - 2548
PB  - Inst. of Electr. and Electronics Engineers
CY  - Piscataway
ER  -