Abstract: | Periodate oxidation of cellulose dyed with vinyl sulfone-type reactive dyes at 32°C in the presence of various concentrations of alkaline earth metal chlorides and a cationic dye-fixing agent has been studied. The extent of the oxidation has been assessed in terms of rate constant, time of half reaction, and percent accessibility to periodate ions. Remazol Black B was used in the study. This dye on reduction with sodium hydrosulfite after reaction with the fiber removes the sulfonic acid group containing a portion of the dye, leaving behind a portion reacted with the fiber and not containing a sulfonate group. The study has also been extended to a few direct dyes which, unlike reactive dyes, have been shown not to inhibit the rate of periodate oxidation of cellulose. |