Abstract: Lignosulfonate (LS) is the byproduct of sulfite pulping process. In this paper vinyl group was introduced into the mole-cule of LS by reacting it respectively with maleic anhydride and acryloyl chloride. Then grafted copolymer of modified lignosul-fonate/acrylate was prepared through emulsion polymerization. It was found that as the dosage ratio of lignin to monomers was 1:5,conversion rate of non-modified LS was only 25.1%, grafting efficiency was 26.3%, grafting rate was 129.5%. For LS modified by maleic anhydride and acryloyl chloride respectively,conversion rates were 81.2% and 83%, grafting efficiencies reached 71.8% and 72.6%,grafting rates reached 378.3% and 341.4% respectively.Furthermore,the structure of modified LS and the morphology of copolymerization emulsion particles were studied by IR and TEM respectively.

Key words: lignosulfonate, maleic anhydride, acryloyl chloride, graft copolymerization