CHARACTERISTIC HYGROSCOPICITY OF BACTERIAL CELLULOSE FLUORESCENT BRIGHTENER COMPLEX

The relation between the structure and hygroscopicity of cellulose-brightener complex and the Cell I, which was regenerated from the complex by dye-extraction, was examined by the vapor phase deuteration-IR spectroscopy method. In 60 min, 37% of the OH groups of bacterial cellulose was deuterated. In contrast, 80 approximately 90% of the OH groups of cellulose in the complex was deuterated in 5 min. A 43.1% portion of the OH groups of regenerated Cell I was deuterated in 5 min and 48.6% in 60 min. The OH groups of the complex showed a broad peak at near 3400 cm-1. In the spectrum, however, absorptions due to intramolecular- and intermolecular-hydrogen bonding, which appeared in that of bacterial cellulose, were not observed. The OD groups of the complex also showed a broad peak at 2517 cm-1, but no absorptions due to intramolecular- and intermolecular-hydrogen bonding appeared. In the OH region, an absorption due to the intramolecular-hydrogen bonding at 3345 cm-1 appeared, indicating the regeneration of Cell I, but the band was broad owing to low crystallinity. The increase in hygroscopicity of the complex is thus attributable to the inclusion of the brightener between the mono-molecular cellulose sheets corresponding to the (110BAR) plane thereby preventing the direct binding of the sheets.