Mercerization is a typical transfer reaction from cellulose I (Cell I) to cellulose II (Cell II) and it is recognized that this transfer is irreversible.
To clear the mechanism of the transition from Cell I to Cell II, the change of the crystal structure and the chain conformation during the mercerization are studied under various conditions by means of wide angle X-ray diffractograms and CP/MAS
13C NMR spectra.
It is observed that Cell I and Cell II show the different
13C NMR spectra resulted from the different chain conformation, as proposed by Hayashi
et al. In sodium celluloses treated with and without fixing the fibers, which show the similar X-ray diffractograms, CP/MAS
13C NMR spectra show different patterns which result from two types of the chain conformation, that is Na-Cell of Cell I type and of Cell II type. By regeneration, the Na-Cell of Cell II type transforms to Cell II independently on the temperatures of washing water. On the other hand, the Na-Cell of Cell I type mostly transforms to Cell I by washing with water at about 100 °C.
抄録全体を表示