| Abstract: | Determinations of reducing and carboxylic acid end groups in hydrocellulose treated with hot alkali showed that the end-wise degradation proceeded to such an extent that some of the molecules were brought completely into solution. The major carboxylic acid end groups formed in reactions competing with the end-wise degradation were 3-deoxyhexonic and 2-C-methylglyceric acids; but 2-deoxypentonic, 2-C-methylpentonic, and minor amounts of aldonic acids were also formed. The formation of these stable end groups explains the observed increase in number average degree of polymerization during the treatment. The ratio between the number of lost glucose moieties and the number of carboxylic acid groups formed in the solid phase was about 170 and was only slightly affected by the duration of the hot alkali treatment. |
