Preparation of amphiphilic carbon black by postgrafting of polyethyleneimine to grafted polymer chains on the surface

To prepare amphiphilic carbon black, we investigated the postgrafting reaction of polyethyleneimine (PEI) with pendant glycidyl groups of grafted polymer on carbon black surface, The grafting of polymers having pendant glycidyl groups onto carbon black surface was achieved by the copolymerization of glycidyl methacrylate (GMA) with methyl methacrylate (MMA) initiated by azo groups introduced onto the surface. Pendant glycidyl groups of poly(GMA-co-MMA)-grafted carbon black was found to react with PEI, and the corresponding polymers postgrafted to the grafted copolymer chains on carbon black surface: the percentage of PEI-postgrafting was readily controlled by the reaction conditions. PEI-postgrafted to poly(GMA-co-MMA)-grafted carbon black, whose PEI postgrafting is 3.9% showed amphiphilic nature and acted as an emulsifier.