Abstract: An anionic surfactant binary copolymer NaOL-AA was synthesized with aqueous solution free radical polymerization using sodium oleate (NaOL) and acrylic acid (AA) as starting materials.The product was applied as the ingredient of waste paper deinking agent.Optimization of conditions for the preparation of the product was conducted taking the deinking effect as criteria.Further,the product was blended with a nonionic surfactant fatty acid methyl ester ethoxylate (FMEE).Structure of the product was characterized by FT-IR;the molecular weight and its distribution of the product were measured by GPC;and the deinking effect of deinking agents containing the product or the blended product,and purchased from market was tested and compared.Results showed that the optimal conditions for the synthesis process are as follows:n(NaOL)∶n(AA)=1∶3;reaction temperature,85 ℃;reaction time,6 h;dosage of initiating agent ammonium persulfate (APS),2% of the mass of total reactants;and pH=8-9.When the blended product at the mole ratio of m(NaOL-AA)∶m(FMEE)=1∶2,the whiteness of the deinked waste paper could achieve 69.8% and the residual ink on the waste paper drops to 44.6 mm²/m².

Key words: deinking agent, sodium oleate, acrylic acid, copolymer, whiteness, residual ink