Preliminary communication of network formation on the soft-mode in ferroelectric LC elastomers

The frequency and temperature dependence of the complex dielectric constant epsilon was measured for the smectic C-smectic A phase transition for a crosslinkable ferroelectric polysiloxane. A stepwise crosslinking shifts the soft-mode absorption to lower frequencies, while an increase in relaxation strength and a broadening of the transition occurs. Whereas the shift of the soft-mode can be simply explained by an increase of viscosity in the resulting elastomer, the other two effects indicate an increase in the cooperativity of the soft-mode fluctuations due to the coupling of dipoles in the network even far from the phase transition.