Recrystallization of the Cellulose I Lattice in Mercerized and Regenerated Cellulose Fibers

Cotton cellulose has been subjected to swelling and stretching treatments under various conditions. It has been found that the cellulose I lattice is highly resistant to alkali attack and difficult to disrupt completely during a single swelling treatment. The residual cellulose 1 “nuclei” grow upon stretching the swollen fibers. The amount of the recrystallized fraction is proportional to the residual cellulose I in the slack-mercerized samples. X-ray investigations carried out on several rayons indicate that the extraneous lattice in the viscose rayons is cellulose I and not cellulose IV, as supposed earlier. This is confirmed by the incomplete conversion of cellulose I to soda-cellulose in “mercerization and ageing” processes and also by the sensitiveness of cellulose I to stretching. Evidence on cuprammonium rayon and Fortisan, which appear to be better dispersed in solution and, therefore, contain no cellulose I, supports this view.