Premium
Further studies on the action of alkali metal hydroxides on cotton
Author(s) -
Zeronian S. H.,
Cabradilla K. E.
Publication year - 1973
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1973.070170217
Subject(s) - swelling , cellulose , alkali metal , boric acid , sorption , reagent , chemistry , degree of polymerization , polymer chemistry , nuclear chemistry , materials science , polymerization , inorganic chemistry , organic chemistry , polymer , composite material , adsorption
X‐Ray diagrams revealed that the conversion of the lattice structure from cellulose I to cellulose II is substantially complete in cotton treated at 0°C with LiOH, NaOH, or KOH of approximately 5 N concentration. With concentrations less than 5 N , there were marked differences in the ability of these reagents to cause lattice conversions in cotton. Below a minimum concentration which is dependent on both the alkali and the treatment temperature, conversion from cellulose I to cellulose II cannot take place in cotton irrespective of the swelling caused by the reagent. We suggest that extensive swelling by one of these alkalis is not sufficient by itself to cause conversion from cellulose 1 to cellulose II and that the concentration of the alkali is of prime importance. There was no direct relation between the swelling induced in cotton by treatment with LiCH, NaOH, or KOH at 0°C and the sorption ratio of the resulting product. Also, although treatment with 5 N KOH caused less swelling than that obtained with either 5 N NaOH or LiOH, KOH reduced the level‐off degree of polymerization (LODP) of cotton most, indicating the importance of the size of alkali cation in reducing crystallite length. In additional experiments, cotton was treated at 21°C with a solution of 4.7 N NaOH to which boric acid had been added. Although the swelling of the cotton was little affected, the addition of the boric acid caused the sorption ratio of the product to decrease, whereas the LODP increased. Also conversion of the lattice structure from cellulose I to cellulose II was inhibited.