Ph.D. Tezi Görüntüleme

       An alternative impedance bridge that has frequencies ranging 1KHz and 100KHz was formed so that we could measure the dielectric parameters of oriented polystyrene (PS) films. Dielectric constants (E^l ), dielectric loss factors (E^H) and loss tangent (tan&) of PS films were measured. The changes of these parameters were observed depending upon intensity and direction of the applied field. The orientation degrees of the films were measured with optic detectors made by using photo resistance and photocell. Infrared dichroism was calculated as R=A_n/A_T for the peak optical densities A_n and A_T.

       In the result of this research, while the parameters (E^l,E^H,tan&) of the films oriented perpendicularly to the surface decreased by increasing of electrical field, those oriented in parallel to the surface increased by increasing of electrical field. This research indicated that the orientation made by electric field was the same as the orientation made by the uniaxial mechanical stretch.

       Keywords : Orientation, Electric Field, Polymer, Polystyrene, Thick Film, Birefringence, Dichroism, Waxs, Saxs, AC Capacitance Bridge

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