Abstract:The SL-AA-MA-APEG copolymer for water-based ink dispersion is synthesized by using lignin sulfonate, acrylic acid, allyl polyethylene glycol and acrylamide as monomer, ammonium persulfate as redox initiator, sodium bisulfite as chain transfer agent. The effect of different reaction conditions on the dispersing properties of copolymer for water based ink pigment has been investigated. The optimum conditions are listed as follows: the mass ratio between lignin sulfonate, acrylic acid and acrylamide is 1:4:4:1, the amount of initiator is 3.5%, the reaction time is 4.5h, the reaction temperature is 90℃. Accordingly, the FTIR proves that the Lignin is successfully grafted. On the other hand, the dispersion of the polymer was characterized and analyzed by SEM, nano particle size analyzer, Ultraviolet spectrograph and rheometer. The results show that the better dispersion effects are achieved when the copolymer mass fraction is 2.5%, the minimum-partical size is 190.1nm. In comparison with commercial WP-A10, the copolymer has a considerable anti-settling properties and optimum performance of the pigment dispersed.