H. G. Shinouda

Effect of acid hydrolysis on the apparent specific volume of viscose rayon

Abstract The apparent specific volumes of viscose rayon and its hydrolysis residues, prepared by the action of 0·2 and 1 N HCl at 100°, were measured dilatometrically in the range 5–50° using toluene as displacement medium. The variation of the specific volume at 20° with the progress of hydrolysis showed a characteristic minimum, dependent on the hydrolytic conditions. These results, with those previously obtained from i.r. studies showed that the crystallinity of the fibre increased till 2·5% dissolution, and then decreased. Also, it was found that the second order transition of viscose rayon is primarily a function of its accessibility rather than its DP.