Modified polymeric flocculants with improved performance characteristics
AssigneeGE Betz, Inc.
InventorsJeffrey H. Peltier, Stephen R. Vasconcellos, Michael R. Wood
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Abstract
Methods for the preparation of high molecular weight cationic poly(meth) acrylamide/quaternary ammonium salt copolymers are disclosed wherein after at least about 50% of the monomers have been polymerized, a cross-linking agent is then added to the reaction mixture on a continuous basis and in the absence of any feed of chain transfer agent. Cationic copolymers so produced exhibit improved floc formation properties and are useful as flocculants and dewatering aids in aqueous systems that include an oily sludge or the like.
Claims17
Improved method for preparing a cross-linked water soluble cationic (meth) acrylamide/quaternary ammonium salt copolymer that is useful as a flocculant, said method comprising 1) initiating polymerization of an aqueous reaction mixture comprising (meth) acrylamide monomers and quaternary ammonium salt monomers to convert said monomers into a copolymer containing reaction mixture comprising cationic poly (meth) acrylamide/quaternary ammonium salt copolymer;
- and 2) cross-linking said copolymer by addition of a cross-linking agent to said copolymer containing reaction mixture;
- wherein said step of 2) cross-linking comprises waiting until about 50% or more of said monomers have been converted into said copolymer and then continuously adding between about 1 ppm to about 500 ppm of said cross-linking agent to said copolymer containing reaction mixture based on the total amount of said reaction mixture in the absence of concurrent addition of any chain transfer agent to said copolymer containing reaction mixture.
Dependencies are inferred from the claim text.