Reversible crosslinking in cellulose. III. Factors controlling the oxidation behavior of mercapto groups in cotton derivatives
✍ Scribed by Sakamoto, Munenori ;Takeda, Junichi ;Yamada, Yoshio ;Tonami, Hiroaki
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1970
- Tongue
- English
- Weight
- 553 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0449-296X
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✦ Synopsis
Abstract
The oxidation behavior of mercaptocellulose prepared from tosylated cotton and of cellulose β‐mercaptoethylaminocarboxylate (RDTC), which was prepared by reduction of a cotton derivative made by the reaction with bis‐β‐isocyanatoethyl disulfide, was studied, and the factors controlling the oxidation behaviors of solid polymeric mercaptans were discussed. RDTC was converted quantitatively to the corresponding disulfide by oxidation under mild conditions. Repeated oxidation–reduction cycles were applied to RDTC to demonstrate complete reversibility of disulfide crosslinking. On the other hand, only a portion of the mercaptan in mercaptocellulose could form disulfide by oxidation. It is considered that the mobility of the mercapto groups necessary for the oxidation coupling is restricted because they are attached directly to rigid cellulose chains. The oxidation of RDTC with air in alkaline medium was studied kinetically. It was found that the oxidation of the mercaptan in paired placement in the cellulose matrix proceeded more than ten times faster than that of the randomly placed mercaptan.