| Popis: |
The regularities of the influence of solvents, introduction of substituents (hydroxypropyl, acetyl, etc.) and degree of etherification of cellulose macromolecules on temperature-concentration boundaries of LC-state in rest and flow are studied. Set of hydroxypropylcellulose (HOPC) samples with the degree of mole substitution from 0.23 to 7.50, cellulose acetates and other lyotropic cellulose derivatives is ayplied. Individual and mixed nonaqueous solvents of different nature were used: polar aprotic (dimethyl-acetamide-DMAA, N-methylpyrrolydone, nitromethane), protonodonating (trifluoroacetic acid, acetic acid), water and others. The physicochemical properties of solutions (phase equilibrium, rheologic, hydrodynamic and volumetric parameters are studied. A model for prediction of anisotropicisotropic transitions in lyotropic solutions of cellulose derivatives is elaborated. |
