This invention relates to a novel class of biodegradable water-soluble graft copolymers having building, anti-filming, dispersing and threshold crystal inhibiting properties comprising (a) an acid functional monomer and optionally (b) other water-soluble, monoethylenically unsaturated monomers copolymerizable with (a) grafted to a biodegradable substrate comprising polyalkylene oxides and/or polyalkoxylated materials.