Abstract: A process for inhibiting scale formation using a low molecular weight hydrolyzed polyacrylamide prepared by a process involving simultaneously and continuously charging separate streams of acrylamide monomer, ammonium persulfate (as catalyst) and mercaptoalkanoic acid (as chain transfer agent) to a reaction zone containing water under reflux, the rate of charging being such that the heat of polymerization is sufficient to maintain reflux in the reaction zone without exceeding the capacity of the condenser to remove the heat of reaction, and then reacting the polymer product with sufficient aqueous caustic to hydrolyze from about 60 to 90% of the amide groups in the polymer product.

Abstract: An anionic polymer of acrylamide having a skewed molecular weight distribution such that about 60% of said polymer has a molecular weight of about 500 to 2,000 and about 10% of said polymer has a molecular weight of about 4,000 to 12,000 has been discovered. The process of manufacturing this skewed molecular weight distribution anionic polymer is described. Its use as a scale inhibitor for controlling the deposition of adherent scales on the walls of vessels or pipes, and as an anti-precipitant for keeping alkaline earth cations in solution is also described. The use of the anionic polymer of acrylamide consisting of a skewed molecular weight could be used in recirculating water systems, boilers, and in evaporative and reverse osmosis desalination systems.

Abstract: A low molecular weight hydrolyzed polyacrylamide having exceptional effectiveness as a scale-inhibiting agent is prepared by a process involving simultaneously and continuously charging separate streams of acrylamide monomer, ammonium persulfate (as catalyst) and mercaptoalkanoic acid (as chain transfer agent) to a reaction zone containing water under reflux, the rate of charging being such that the heat of polymerization is sufficient to maintain reflux in the reaction zone without exceeding the capacity of the condenser to remove the heat of reaction, and then reacting the polymer product with sufficient aqueous caustic to hydrolyze from about 60 to 90% of the amide groups in the polymer product.