Polyacrylamide-phosphonate flocculants and methods of making

A process for the preparation of a water treatment composition in an aqueous medium comprising an anionically modified acrylamide polymer formed by reacting an acrylamide polymer with phosphorous acid, said modified polymer having at least 5 mole percent phosphonate groups based on the acrylamide content of the acrylamide polymer and having a molecular weight of from about 40,000 to about 18,000,000, the pH of said composition being adjusted to at least about 7.7.

A composition in an aqueous medium comprising an anionically modified acrylamide polymer formed by reacting an acrylamide polymer and phosphorous acid, said modified polymer having at least about 5 mole percent phosphonate groups based on the acrylamide content of the acrylamide polymer and having a molecular weight of from about 40,000 to about 18,000,000, said modified polymer further prepared by dilution with water after said reaction, the pH of said water being adjusted prior to dilution to result in a diluted product having a pH of approximately 7.7 to about 8.4.

A process for the preparation of a water treatment composition in an aqueous medium comprising an anionically modified acrylamide polymer formed by reacting an acrylamide polymer with phosphorous acid, said modified polymer having at least about 5 mole percent phosphonate groups based on the acrylamide content of the acrylamide polymer and having a molecular weight of from about 40,000 to about 18,000,000, and then diluting the resulting composition with water, the pH of said water being adjusted prior to dilution to result in a diluted product having a pH of approximately 7.7 to about 8.4.