抄録
Rayons were heat-treated with hot-water or steam at above 100°C as described in the previous papers and change in the fine structure was studied by X-ray method. The following results are obtained;
(1) The higher the temperature of heat treatment, the sharper is the crystalline diffraction pattern, which is considered to represent an increase in crystallinity and packing perfection of the cellulose chains within the crystallites.
(2) The diffraction of cellulose-IV appeares in such a short time treatment as 15 sec. and its amount formed by heat-treatement is larger in the tire-cord rayon than in the textile rayon or cuprammonium rayon.
(3) Although there is a large difference in depressing effect of swelling of rayon between the hotwater treatment and steaming, little difference is detected in the X-ray crystallinity. Therefore the decrease of swelling may be ascribed to the formation of junction points in amorphous parts of rayon.
