Abstract
Bleaching effect of sodium percarbonate was evaluated by change both in colors of Acid Orange R (C. I. 15575) solution and the surface reflectance of unbleached cotton cloth. Samples of sodium percarbonate were stored in desiccators which had been controled to have relative humidities (RH) of 40, 60 and 80% respectively, and stability of the samples was checked by available oxied contents.
The obtained data were compared with those of sodium perborate which had already been known as an effective bleaching agent.
The results were as follows :
1. The stability of sodium percarbonate stored in 40 and 60% RH was satisfactory, but the stability of that stored in 80% RH was very poor.
2. The bleaching effect of sodium percarbonate was superior to that of sodium perborate, and the temperature dependence of the effect of the former was greater than the latter. The bleaching effect of sodium percarbonate on cotton cloth at lower temperatures (20, 40 °C) was unsatisfactory.
3. Practicable conditions of bleaching cotton by sodium percarbonate are : Most recommended - Concentration 1 %, Temperature 70 °C, Preferable - Concentration 0.5 %, Temperature 60 °C.
