Synthesis And Properties Of Hydrophobically Associating Water-soluble Polymer

The polyacrylamide is widely used in oil-fields, but some problems of polyacrylamide have been found such as the worse tolerance of high temperature, high salinity and high shear rate in its application. In order to solve the problems, in the paper a newly hydrophobically associating water-soluble polymer was synthesized through copolymerization of polyacrylamide and three sorts of hydrophobic monomers which were synthesized. The newly polymers can resist the high temperature, high salinity, high shear rate and have the thickening properties with the salinity and temperature in some degree.Three sorts of hydrophobic monomers were synthesized through the direct esterifying reaction, and the optimum reaction conditions were determined. Thereafter, the monomers reacted with acrylamide respectively through micellar copolymerization. As expected, three series of hydrophobically associating water-soluble polymers were synthesized. Furthermore, it was fully analyzed and discussed how the viscosity of copolymer solution was affected by the experimental factors, and then the optimum synthesis conditions were determined. The hydrophobic monomer and polymer were characterized by the infrared absorption spectrum, and then the molecular structure was confirmed. In addition, it was investigated how the properties of the polymer solution were affected by the polymer concentration, the hydrophobic monomer concentration, the hydrophobic chain length, salinity, temperature and shear rate. The experimental results showed that a critical associating concentration would appear with the increase of polymer concentration. Above the critical concentration, because of the intermolecular hydrophobic association, they showed remarkable tolerance of high salinity, high temperature and high shear rate. We also found that these properties of copolymer of acrylamide and n-dodecyl acrylate (AMA₁₂) were best in the three series of polymers, for the hydrophobic chain of AMA12 was the longest, and the hydrophobic associating affection was the strongest. Through studying how the viscosity of hydrophobically associating polymer solution was affected by the surfactant, it was found that adequate surfactant could increase the viscosity of copolymer solution greatly.