Studies of lyotropic liquid crystalline mesophases of some novel regioselective substituted cellulose derivatives .1. Synthesis and characterization

Novel regioselective substituted cellulose derivatives, suitable for investigations of their liquid crystalline phase behaviour, were synthesized. The derivatives, tricarbanilates with varying substituents at the phenolic residue, were characterized according to their molecular weight and molecular weight distribution by means of size exclusion chromatography coupled with low angle laser light scattering (SEC/LALLS). A simple new method is presented, which allows the calculation of the constants K and alpha of the Staudinger-Mark-Houwink (SMH) equation, the viscosity-average molecular weight (M) over bar(eta) as well as the intrinsic viscosity [eta] from the light scattering calibration curve of an SEC experiment. The calculated values of the intrinsic viscosity are in good agreement with those derived from measurements with a low-shear viscometer. A plot [eta] vs. weight-average molecular weight (M) over bar(w) shows, that a substitution at the C-2 and C-3 position of the glucosic unit with 3-chlorocarbanilate leads to a well pronounced enlargement of the polymer dimensions which is mirrored by larger values of [eta] at the same (M) over bar(w) as compared with other cellulose derivatives.