CHANGE OF THE MICROSTRUCTURE OF MICROCRYSTALLINE CELLULOSE WITH GRINDING AND COMPRESSION

The microstructure of microcrystalline cellulose was investigated by u se of a radial distribution function (RDF) based on the intensity of X -ray scattering data. Changes in the microstructure of the cellulose a s a result of grinding and compression were detected by use of the RDF . The RDF of intact microcrystalline cellulose had peak maxima corresp onding to distances of approximately 1.5, 2.6, 5.0, 8.2, 13.3 and 17.0 Angstrom. The first two corresponded to the intramolecular atomic dis tances; other peaks were attributable to the intermolecular (inter-fib re) atomic distance. Changes in the RDF as a result of grinding indica ted that the regular intermolecular atomic arrangement was gradually l ost. Compression resulted in formation of long-range (> 20 Angstrom) o rdering of the intermolecular (inter-fibre) atomic arrangement. These results show that RDF analysis is suitable for monitoring changes in t he structure of microcrystalline cellulose which occur as a result of grinding and compression.