Caractérisation de structures de fibres de cellulose régénérée par l'étude détaillée de leurs diagrammes de diffraction de rayons X et par divers traitements de gonflement. I. Étude détaillée des diagrammes de diffraction de rayons X de fibres et de feuilles d'hydrate de cellulose

The authors have designed different experimental devices for the realization of strictly monochromatic diagrams of orientated samples, the fully automatic recording of numerous radial tracings thereof, and the careful analysis of their components. Because of the difficulty of interpretation of high tenacity rayons diagrams (due to poor resolution of peaks and the occurrence of cellulose IV) preliminary experiments have been carried out, with (a) particular examination of rayons containing no cellulose IV, (b) application of moderate swelling treatments causing a sharpening of diffraction peaks, (c) x‐ray examination of planar‐oriented cellulose samples giving “simplified” diagrams when irradiated under particular conditions. The information obtained from these experiments establishes the occurrence of a noncrystalline anisotropic part in regenerated cellulose fibers. There is a twofold orientation of the “amorphous” background in regenerated cellulose sheets. This is in favor of the occurrence of doubly anisotropic “pseudo‐amorphous” parts whose structure is of a paracrystalline type with superimposed dislocations. On the basis of different observations made on photometric tracings, a nonsubjective method is suggested for the individual evaluation of A0, A3 + A4 of cellulose II, (002) and (101 + 101) of cellulose IV, pseudo‐amorphous and amorphous components in regenerated cellulose diagrams. Individual orientation factors may be defined and measured for the components.