抄録
The degradation of cellulose accompanied by bleaching was examined at various levels of pH using cellophane and tea-dyed cellophane. Sodium percarbonate was used as a bleaching agent and sodium hypochlorite was also used for comparison. The degree of degradation of cellulose was determined by measuring the viscosity of bleached cellophane in cuprammonium solution.
The main results obtained are as follows.
1) The degree of degradation of cellulose accompanied by bleaching the cellophane with sodium percarbonate was lower than that with sodium hypochlorite.
This seems to come from the difference in oxidation-reduction potential of the two bleaching agents.
2) The curve for the degree of degradation of cellulose and pH of the aqueous solution of sodium percarbonate showed a maximum at pH 11.
3) The rates of decoloration of aqueous extracts from tea and of the tea-dyed cellophane were found to be greatest at pH 11.5.
