Patent ID: 7473334

Claim:
A method of preparing a modified diallyl-N,N-disubstituted ammonium halide polymer having a cationic charge of about 1 to about 99 mole percent comprising (a) preparing an aqueous solution comprising one or more diallyl-N,N-disubstituted ammonium halide monomers, about 35 to about 85 percent of the total acrylamide monomer, about 0.1 to about 150,000 ppm, based on monomer, of one or more chain transfer agents and optionally about 1 to about 30,000 ppm, based on monomer, of one or more cross-liking agents; (b) initiating polymerization of the monomers; (c) allowing the polymerization to proceed to at least about 5 percent diallyl-N,N-disubstituted ammonium halide monomer conversion and at least about 20 percent acrylamide monomer conversion; and (d) adding the remaining acrylamide monomer and allowing the polymerization to proceed to the desired endpoint, wherein the modified diallyl-N,N-disubstituted ammonium halide polymer has a RSV of from about 0.2 to about 12 dL/g and a charge density of less than about 7 milliequivalents/g polymer.