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New results concerning the behavior of cellulose acetate in solutions and films by means of CD measurements
Author(s) -
Meißner D.,
Einfeldt J.,
Schareina T.
Publication year - 1999
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/(sici)1097-0282(199908)50:2<163::aid-bip5>3.0.co;2-0
Subject(s) - acetonitrile , chemistry , cellulose acetate , cellulose , solvent , polymer , macromolecule , circular dichroism , spectral line , amorphous solid , crystallography , organic chemistry , biochemistry , physics , astronomy
Cellulose acetate (DS = 2.45) was extensively investigated by Circular Dichroism (CD) in acetonitrile and dioxane. We found great differences between the CD spectra of a 1 wt % acetonitrile solution and the corresponding dioxane solution of cellulose acetate (CA) indicating that the macromolecules exist in those solutions in different molecular arrangements (e.g., persistence length, solvatation shell). The resulting morphologies could be transformed reversibly into each other, as we found by measuring the CA in mixtures of both solvents. Solid CA films show discernible CD spectra depending on the solvent they were evaporated from. In this way, we prepared solid films of the same polysaccharide owning different chiral properties. Furthermore, changes in the spectra occurred with increasing CA concentration. Basing upon our findings, some general statements concerning the polymer behavior of CA are possible. © 1999 John Wiley & Sons, Inc. Biopoly 50: 163–166, 1999