Structural Orientation in Cellulose Acetate Filaments and Its Relation to the Dichroism of Adsorbed Dyes

Abstract

Factors influencing structural orientation and oriented adsorption of dyes in cellulose acetate filaments were studied using methods based on x-ray reflections and on dichroism. The deriva tion of a method of computing the percentage orientation from the density of the 002 ring is given. A method for determining the percentage orientation using dichroic dyes is described. In evalu ating the data obtained by the latter method, the x-ray data were used as standard. The dyes examined are classified according to their ability to adsorb directionally on the cellu lose acetate substrate. Dyeing conditions affecting results obtained by means of dichroism are discussed in relation to filament structure. Orientation measurements by both methods were made on continuous-filament yarns drafted to various extensions. The values obtained by the x-ray method were generally higher than those obtained by the method based on dichroism.