STRUCTURAL FEATURES OF CELLULOSIC CHANGE IN ALKALI-TREATED JUTE STICK - AN INFRARED-ABSORPTION STUDY

The cellulosic change has been discussed in terms of absorption ratio of certain infrared bands. It is shown that the absorption of O—H and C—H stretching frequencies decreases up to 25% alkali treatment and the absorption of β‐glucosidic band increases with increasing alkali strength in swelling. The anomalous behavior in the absorption of these bands at 18% alkali treatment might be due to partial mercerization. A new type of hydrogen bonding is proposed where C6 hydroxyl groups are involved in a bifurcated six‐membered hydrogen bonding system giving more crystalline nature to mixed lattice of cellulose. The O2 hydroxyl proton forms hydrogen bond with O3 of the same unit and with O'2H of its antiparallel chain. It is also noted that the presence of lignin has no significant effect on cellulosic transition. Copyright © 1990 John Wiley & Sons, Inc.