MESOMORPHIC PROPERTIES AND SANS CONFORMATIONAL STUDY IN DIFFERENT LIQUID-CRYSTALLINE POLYMERS

We report an overview about chain-conformation informations given by small angle neutron scattering (SANS) studies of different kinds of Liquid Crystalline Polymers. We conclude that in the prolate nematic phase the chains are directly connected to the orientational order and the chain extension strongly depends on microscopic considerations concerning the coupling mesogen-chain. The behavior is markedly different when the backbone anisotropy is oblate because the chains are hence affected by the smectic layering order (even at the scale of fluctuations in a high temperature nematic phase). In this latter case, since the chains are more or less confined in a 2D Gausssian geometry, they locally do not follow the director and the chain anisotropy mainly depends on the strength of the smectic layering.