Synthesis and Aqueous Solution Properties of a Novel NonIonic, Amphiphilic Comb-Type Polyacrylamide

Nowadays comb-type polyacrylamides are deemed to be the most promising oil-displacing agent in the field of enhanced oil recovery (EOR). We describe the synthesis of a nonionic, amphiphilic macromer (OPAE) with acrylic acid (AA) and t-octylphenoxypolyoxyehylene (OP) by an esterification reaction. The macromer was then copolymerized with acrylamide (AM) under a free radical initiator system and a comb-type modified polyacrylamide (MPAM) was obtained. The structures of OPAE and the MPAM were characterized by Fourier transform infrared (FTIR), 1H nuclear magnetic resonance (NMR) and dynamic laser light scattering. In order to compare with partially hydrolyzed polyacrylamide (HPAM), the aqueous solution of the MPAM had a higher apparent viscosity, especially in brine. We suggest that the reason was that the branched chains enhanced the rigidity of the MPAM, and made the molecules have a larger hydrodynamic radius, especially in brine, endowing the copolymer with excellent salt tolerance.