Chemical changes produced in the cellulose macromolecule by oxidizing agents Communication 9. Oxidation of cellulose by nitrogen dioxide

Abstract

1. The oxidation of cellulose by nitrogen dioxide does not consist in the specific oxidation of primary alcohol groups, this reaction being always accompanied by the oxidation of secondary alcohol groups. 2. In celluloses oxidized with nitrogen dioxide, most of the carboxyl groups formed are in the 6-positions of the glucose residues. Some of the carboxyl groups are formed as a result of oxidative scission of the pyran ring. 3. Celluloses oxidized with nitrogen dioxide contain many carbonyl groups (as many as 10 groups per 100 glucose residues, the number of carboxyl groups then being 65). In freshly oxidized preparations most of the carbonyls are keto groups, and the content of aldehyde groups is low (not more than 0.3 per 100 glucose residues). 4. Celluloses oxidized with nitrogen dioxide do not contain peroxy and carbonic ester groupings. All of the nitrogen in these oxycelluloses is present in the form of nitric ester groupings. 5. The experimental material obtained supports the suggestion that oxidation proceeds with intermediate formation of nitric esters. it is necessary to assume that ester formation and the oxidative hydrolysis of the product can occur not only at primary OH groups, but also at secondary OH groups in the glucose residues of the cellulose macromolecule.