Patent ID: 8202946

Claim:
A process for preparing a graft copolymer of a polyaspartate comprising: providing an amount of sodium poly(aspartate); adding water to the sodium poly(aspartate); mixing the water with the sodium poly(aspartate) to dissolve the sodium poly(aspartate) and form a solution; adding ferrous ammonium sulfate in the amount of about 0.1 to about 30 percent by weight of the solution to the solution; bubbling the solution with nitrogen while stirring the solution; adding hydrogen peroxide in the amount of about 0.1 to about 50 percent by weight of the solution to the solution; adding at least one monomer to the solution either before or after adding the hydrogen peroxide in order to form the graft copolymer; continuing treatment with nitrogen under a nitrogen blanket with stirring at room temperature to form the graft copolymer; and recovering the graft copolymer.