Synthesis of lignosulfonate surfactants from waste water of kraft pulping process, used in the pesticide formulation

Abstract

Lignosulfonates have been used as surfactants in many field of industry. Based on the survey of several main lignosulfonate synthesis methods, the ethylsulfonation of lignin, obtained from black liquor, a waste water from kraft pulping proces was investigated. The mixture offormalin and sodium sulfite was selected and used as methylsulfonation agent. The suitable conditions for this reaction were examined and optimized (molar ratio of reactants, time of reaction, amount of sulfonation agent...). The products were identified and characterized by Infrared Spectroscopy and sulfonation degree measuring (through sulphur element determination in the product). The products are successfully used as multifunctional surfactants in the formulation of two commercialfungicides: Copper oxychloride 30WP and Sulphur 80 WDG.