AbstractsChemistry

The object of the present research was to establish the effect of pH on the degree of chlorination and degradation of lignin sulphonic acid, withthe view of its possible application to multi-stage bleaching.Chemical change is indicated by variation in chlorine, sulphur and methoxyl content. The extent of chlorination is an important factor in bleachingdue to (i) the instability of chlorinated organic compounds to subsequent oxidation, (ii) the increased solubility of chlorinated residues indilute alkali. Decrease in sulphur and methoxyl content may be considered as an index of chemical degradation. [...]