| 摘要 |
A sulfonated lignin composition suitable for use as an additive in other chemical compositions and processes having essentially complete water solubility in aqueous medium at all pH levels, and a method of producing such sulfonated water-soluble lignin products by reaction of an unsulfonated or a sulfonated starting lignin compound with oleum, while maintaining the temperature of the reaction below 40 DEG C. for a sufficient time to sulfonate the same. Oleum sulfonation provide an increases the organically bound sulfuonic acid content of the starting lignin compound of at least about 4.2 moles sulfonic acid per mole of lignin, while providing essentially complete water solubility of the product at all pH levels.
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