Characterization of acidic groups in oxycelluloses. I. Identification of various functional groups

摘要

AbstractA large number of oxycelluloses were prepared and modified further by treatment with sodium borohydride as well as chlorous acid, and qualitative color tests were carried out to detect the presence of various functional groups. Uronic acid groups were found to be present in most of the samples. Enediol groups were not detected in any of the samples, although the samples after sodium carbonate treatment gave distinct color tests for enediols, indicating the presence of α‐hydroxymonoketo groups. Characteristic color tests for lactones were observed for most of the samples. The intensity of color developed in the lactone test was, however, found to decrease progressively on contact with a KI–KIO3mixture for various periods. The difference in the values of carboxyl content between the methylene blue method and the iodometric method is thus mainly caused by the opening of lactones in the latter me