Characterisation of acidic groups in oxycelluloses. II. Estimation of carboxyl groups and lactones by iodometric method

✍ Scribed by W. B. Achwal; Gouri Shanker

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 700 KB
• Volume: 16
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1972.070160801

✦ Synopsis

Synopsis

A differentiation between free carboxyl and various lactone groups in oxycelluloses was carried out based on the variation in their reaction rates with KI-KI03 solution. An attempt has been made to identify the various lactone groups present by comparison of the results of different oxycelluloses as well as study on some model compounds. A characteristic and group spectrum was determined for each oxycellulose. On blocking the free carboxyl groups by zinc acetate treatment, the results for the nature and amounts of various lactones present are in good agreement with the results for oxycelluloses themselves. Sodium borohydride treatment for 120 hr has been found to be incapable of reducing all the lactones present. An appreciable decrease in the value for glucono-6lactone was observed, while glucuronic acid lactone was only partially attacked. Treatment with chlorous acid resulted in an increase in the values for free carboxyl as well as lactones for all oxycelluloses.