A novel water-soluble polymer was prepared by copolymerization and sulfomethylation using acrylamide (AM) and N-allylbenzamide (NABI) as raw materials under mild conditions. The effects of ratio of AM to NABI, initiator concentration, reaction temperature, pH, and monomer concentration on the copolymerization were studied. The sulfonates copolymer was characterized by infrared (IR) spectroscopy, 1H NMR spectroscopy, elemental analysis, and atomic force microscopy (AFM). It was found that the sulfonates copolymer could achieve up to 25%, 30% retention rate of the viscosity at a high temperature (120 degrees C) and a vigorous shear condition (1000 s1). It was also found that the sulfonates copolymer had moderate salt tolerance (NaCl, CaCl2, and MgCl2 center dot 6H2O) and its viscosity could be restored to the original value when the shear rate changed from 170 to 510 s1 and 510 to 170 s1. At last, the enhanced oil recovery (EOR) of the sulfonates copolymer was tested by core flood, and with up to 10.6% EOR was afforded in presence of 5000 mg/L NaCl brine at 60 degrees C. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013