LIGHT-SCATTERING STUDIES ON SOLUTIONS OF CELLULOSE IN N,N-DIMETHYLACETAMIDE i LITHIUM CHLORIDE

These studies are based on the solvent System N,N-dimethylacetamide (DMAc)/LiCl which is used, e. g., for the determination of the molecular weight distribution of cellulosic Substrates by size exclusion chromatography (SEC).. Results are presented on static and dynamic laser-light-stattering experiments carried out in the concentration range employed in SEC and discussed in terms of the solution state. The influence of two different methods of cellulose activation (swelling in water and liquid ammonia followed by a solvent exchange) was investigated. Cellulose samples with high or low molecular mass were examined. In dependence on the concentrations of salt and celluilose during the dissolution process a molecular dispersion of the cellulose could be fotmd in diluted solutions.