A graft copolymer dispersant (binder) having a weight average molecular weight of about 5,000-100,000 wherein: (1) the graft copolymer has a polymeric backbone formed by polymerizing ethylenically unsaturated monomers; (2) the graft copolymer has macromonomer side chains attached to the backbone at a single terminal point that have weight average molecular weights of about 1,000-30,000 and are formed from by polymerizing ethylenically unsaturated monomers in the presence of a cobalt chain transfer agent. The graft copolymer further contains about 2 to 70% by weight, based on the weight of the graft copolymer, of polymerized constituents having a phosphate moiety or phosphoric acid moleties that are polymerized into the backbone, the side chains, or both. The graft copolymer is neutralized with an inorganic base or an amine.