Passive microrheology for measurement of gelation behavior of a kind of polymer gel P(AM‐AA‐AMPS)

One kind of polymer gel P(AM‐AA‐AMPS) was prepared by radical aqueous copolymerization, using acrylamide (AM), acrylic acid (AA) and 1‐acrylanmido‐2‐methylpropanesulfonic acid (AMPS) as monomers, N,N‐methacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator. The microstructure and molecular structure of the polymer gel were characterized by environmental scanning electron microscope (ESEM), infrared spectrometer (IR) and thermal gravity analysis (TGA). Main factors affecting the gelation behavior of P(AM‐AA‐AMPS) were qualitatively and quantitatively studied by multi‐speckle diffusion wave spectroscopy (MS‐DWS) technology, and the elasticity index (EI) and macroscopic viscosity index (MVI) were introduced to evaluate the elasticity and viscosity of the polymer gel. The results show that the synthesized P(AM‐AA‐AMPS) polymer gel has three‐dimensional network structure gel with thermally resistant and salts tolerant groups. The EI and MVI of solution increase abruptly during the gelation time and the two indexes tend to stabilize. Under certain conditions, with the increase of reaction temperature and concentration of monomers and initiator, the gelation time of polymer gel gets shorter and the gel strength increases; with the increase of concentration of crosslinker, the strength of polymer gels increases, while the gelation time remains almost unchanged. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43364.