Phase and structural transformations of liquid-crystalline polymer systems in the mechanical field

Phase LC transitions and the structure of blends based on cyanoethyl cellulose with DMA and DMF, poly-(gamma-benzyl-L-glutamate) with DMF, and hydroxypropyl cellulose with ethanol, acetic acid, DMA, DMF, and water have been studied under static conditions and in a mechanical field. With decreasing molecular mass of the polymer, the boundary curves separating isotropic from anisotropic solutions are shifted to higher concentrations and lower temperatures, in agreement with the Flory theory. When solutions are deformed, the cholesteric type of liquid crystals is transformed into the nematic type; this process is accompanied by the formation of domains in solutions, and the corresponding temperature-concentration boundaries of the LC phases are changed. As the molecular mass of the polymer increases, the ability of macromolecules to orient under the shear field decreases.