Dielectric investigations of a chiral monomer and side chain polymer

The dynamics of different collective and non-collective modes in a chiral l iquid crystalline monomer and its side-chain polymer have been studied by d ielectric spectroscopy. The monomer system enabled us to study the temperat ure dependence of the dielectric permittivity when crossing the transition from the SmA* phase directly to the crystal phase. Although the polymer sys tem has a SmA* to SmC* transition, we found that the temperature dependence of the dielectric permittivity is radically different from the normally ob served behaviour in these phases. The contributions from the soft and Golds tone modes, respectively, are extremely low, a result which is related to t he very low value of the spontaneous polarization of the material. At lower temperatures in the SmC* phase, a very weak dielectric absorption located around 50 kHz is observed and discussed in terms of the liberational motion of side chains around the polymer main chain.