To increase the dispersion stability of carbon black in water

polymers with sulfonic acid groups were grafted onto the surface of carbon black．Under the effect of ultrasonic wave

sodium allyl sulfonate (SAS) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) were copolymerized with acrylic acid and grafted onto the surface of carbon black

respectively by means of redox of eerie ion and nitric acid．The copelymerization conditions and dispersion stability of grafted carbon black were discussed in detail．It was found that the introduction of sulfonic acid groups improved the dispeion stability of carbon black in water obviously．It was also noticed that AMPS was easier to copelymerize with acrylic acid compared with SAS．For obtaining the highest grafting percentage

SAS and AMPS both had an optimal quantity when the weight of acrylic acid was constant and the ratios of them to acrylic acid (in weight) were within 0.15～1.0．