A high mol. wt. water sol. acrylamide based polymer having improved flocculating and dewatering properties is provided. The polymer is prepd. by a process in which a small quantity of a chain branching agent is added to the polymn. reaction mixt. continuously or stepwise while the monomers are polymd. The polymer exhibits intrinsic viscosity >2 dL/g (1 M NaCl) and sedimentation coeff. within the sol. portion >6.17 * 10-13 s in 0.015 M NaCl and is useful in solid/liq. sepns. such as flocculants and coagulants in wastewater treatment applications, and as thickening agents. A typical polymer was manufd. by water-in-oil emulsion-polymn. of 60 mol% acrylamide with 40 mol% dimethylaminoethyl acrylate Me chloride while adding 4-16 ppm methylenebisacrylamide in the presence of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) and Na2S2O5. [on SciFinder (R)]
Urs von Gunten, Florian Frédéric Vincent Breider, Margaux Océane Voumard