Phase diagram of mesomorphic cellulose derivatives solutions

Cellulose-Based Fibers from Liquid Crystalline Solutions

“…This indicates that unlike steady shear, dynamic shear is not responsible for driving the thermodynamic transition of the anisotropic phase to a different concentration (30). Previous investigators have made similar observations (22,24,26,30). The overall magnitude of the dynamic shear viscosity peak decreases as the frequency increases.…”

“…All four cellulose ester samples exhibit an increase in viscosity with increasing concentration up to a maximum before decreasing with further increase in concentration (i.e., after Vp c ). Such an anomalous viscosity behavior is typical for liquid crystalline solutions, and this has been shown earlier for cellulose acetate (22,24), ethyl cellulose (25), hydroxypropyl cellulose (24,26), cellulose triacetate (27), and cellulose acetate butyrate (12,28). This change in viscosity is due to a change in the structure of the solutions.…”

“…The results (Table I) indicate that OSOH is almost constant for all four cellulose ester derivatives with the exception of CA; that molecular weights differ only by a factor of 1.5 to 2; that the Mark-Houwink-Sakurada (MHS) constant is almost constant by classifying all four cellulose esters as semi-flexible polymer chains (a « 0.90); and that intrinsic viscosity varies by less than a factor of 1.4. Although it is recognized that all factors, i.e., OSOH (22), molecular weight (10,11,14,22), chain flexibility (6), and intrinsic viscosity (10,11), influence liquid crystalline solution properties, the cellulose ester derivatives employed in this Determined by difference.…”

Novel cellulose derivatives. I. Liquid crystal phase formation in tri‐O‐α‐naphthylmethyl cellulose solutions

“…While not performed on tri-0-a-naphthylmethyl cellulose, we have performed the HETCOR on similar arylmethyl cellulose derivative^.^ We found little variation in carbon resonances among arylmethyl celluloses, and therefore base these carbon assignments on previous experiments with benzylated cellulo~e.~ The resulting carbon assignments (Table 11) were checked using Distortionless Enhancement Polarization Transfer (DEPT) . DEPT distinguishes methyl, methylene, and methine carbons, and therefore supported the assignment of methylene carbon 6 and the 3 methylene benzyl carbons (Fig. 2 ) .…”

Thermal and structural properties of tri‐O‐substituted cellulose ethers

“…51, endothermic peaks coincide well with the solid-smectic and smectic-nematic transformation points, respectively, which were determined by heating on a hot stage of the microscope with crossed polarizers. The endothermic peak around 200°C (11) should be assigned to the nematicisotropic transformation. In the second heating run (V), however, the clear endothermic peaks due to the transformation points could not be detected in contrast to the first heating runs.…”