INFLUENCE OF SPACER LENGTH ON THE DIELECTRIC-RELAXATION OF A SIDE-CHAIN LIQUID-CRYSTAL POLYMER

The dielectric relaxation study on a set of polyvinylether based cyano biphenyl side chain liquid crystal polymers with three different alkyl spacer lengths of 7, 9, and 11 shows that the spacer decouples the mo tion of the mesogen from the polymer backbone so that both the low-fre quency delta process and the high-frequency alpha process of the side group have been detected in smectic A phase. At a given temperature th e relaxation frequency increases with spacer length for the alpha proc ess. This trend is also observed for the delta process except for the longest spacer length.