DIELECTRIC-SPECTROSCOPY OF AN ALIGNED LIQUID-CRYSTALLINE SIDE-CHAIN POLYMER USING HIGH-PRESSURES

The complex permittivity of a liquid crystalline side group polymer has been measured at pressure from ambient up to 300 MPa. The samples were initially not aligned, then planar and finally homeotropically aligned by the field of a 7.2 Tesla magnet. Temperatures ranged up to 130 degrees C, and measurement frequencies from 5 Hz to 5 MHz. The equilibrium permittivity Es has been interpreted in terms of an effective dipole moment mu. The frequency of maximum loss has been analysed in terms of enthalpy of activation and volume of activation for alpha and beta relaxation processes.