Magnetic effects and viscosity in the nematic phase of a polymer series

Magnetic measurements were made on a series of polyesters in their nematic state and compared to their apparent viscosity at the same temperature. At similar molecular weights, the length of a flexible segment in the main-chain polymer plays an important role in both the magnetic orientation effects and the apparent viscosity behavior. Moreover, on cooling from a perfectly oriented nematic sample, the alignment remains down to room temperature. In contrast with nematic monomers, these polymers behave like solids, even at the lowest velocity of a rotating magnetic field.