The effect of NaCl on the solution properties of a betaine-type amphiphilic polymer and its performance enhancement mechanism

The amphiphilic random copolymer poly (AM-co-MABPS) (PAMB) was prepared by free radical polymerization with acrylamide (AM) as a hydrophilic monomer and N-methyl-N-allylhexyl benzoyl propane sulfonate (MABPS) as a hydrophobic monomer. The analysis of its structure and composition is based on FT-IR, 1 HNMR, and element analyzer. The solution properties of PAMB are determined by various measurements, including a viscometer, SEM, AFM, fluorescence spectrometer, and rheometer. The results show that the hydrophobic groups introduced into PAMB can self-associate to form a spatial network structure in aqueous solution. PAMB has a lower critical association concentration in brine compared to pure water, and this effect is more pronounced in brine with a higher salinity. The solution properties of PAMB have been significantly improved in brine, and the enhancement mechanism has also been revealed. These impressive properties make this type of copolymer have the potential to chemical flooding for enhanced oil recovery in high-salinity reservoirs.