Characterization and fiber formation of liquid crystalline cellulose derivatives

Better solvents produced an anisotropic phase with a more detailed structure as observed by Polarizing Light Microscopy and SALS. Similar behavior is observed with polymers of increasing bulk crystallinity. Better solvents are found to yield lower critical concentrations and lower biphasic spans. The viscosities of concentrated solutions were found to undergo a maximum and minimum upon transition from isotropic to biphasic to anisotropic phase. The stress optical coefficient of cellulose acetatebutyrate melt spun fibers was found to be one order of magnitude lower than anisotropic solutions. Anisotropic dopes were found to be easier than isotropic dopes to dry jet wet spin. Fibers spun from anisotropic dopes of cellulose acetatebutyrate were found to be weakly crystalline, whereas the melt spun fibers were amorphous. An attempt has been made to hypothesize the mechanism of formation of liquid crystals from cellulose derivatives. The conformation change upon the influence of the solvent was concluded to be dominating.