| Polyacrylamide (PAM) is a kind of water soluble polymer, and is widely used in oil field. The hydrophobic associating water-soluble polyacrylamide is one of the main development trends of polyacrylamide polymers. In this paper, considering the influence of amphoteric monomer and hydrophobic monomer at the same time, acrylamide react with them respectively, and three new kind of water-soluble polyacrylamide were synthesized. Then we studied the influence of different factors on the solution aggregation behavior and application performance.1. A series of hydrophobic association water-soluble copolymer PADM were prepared by the micellar copolymerization of acrylamide (AM), amphoteric monomer 3-[N-(2-methacryloylethyl)-N,N-dimethylammonio]-propane sulfonate (DMCPS) and hydrophobic monomer methyl styrene (a-MSt) using sodium dodecyl sulfate as emulsifier. The structures of the copolymers were characterized by infrared spectrum, nuclear magnetic resonance spectrum (NMR), element analysis (EA) and static light scattering (SLS). The influence of the polymer concentration, temperature, inorganic salt type and concentration on the the aggregation behavior of copolymer molecules in solution were studied by surface tension, fluorescence spectrum, resonance scattering method and dynamic light scattering method. The experimental results showed that PADM have good water solubility, surface activity and hydrophobic association behavior. The critical associating concentration of PADM is 0.1 mg·mL-1, and temperature and salt can affect their aggregation behavior. Due to PADM consisting of benzene ring structure, so we can analysis aggregation behavior by fluorescence spectrometry analysis without additional probe, which make the test more convenient. In addition, PADM still have good viscosity retention rate under high shear rate and high temperature, the test showed that PADM have good heat and salt resistance because of the join of amphoteric monomer DMCPS and rigid structure of a-MSt monomer.2. A series of hydrophobic association water-soluble polymer PADB with long hydrophobic chain were prepared by soap-free emulsion copolymerization of acrylamide (AM),3-[N-(2-methacryloylethyl)-N,N-dimethylammonio]-propane sulfonate (DMCPS) and poly(ethylene glycol) behenyl ether methacrylate (BEM). BEM is a new kind of acrylate macromolecular monomer, in which the length of PEO chain is 25 and alkyl chain is 22. The structures were characterized by IR,1H-NMR, EA and SLS. The aggregation behavior were studied by the methods of fluorescence spectrum, resonance scattering, and dynamic light scattering. Finally we mainly explored emulsifying ability, wettability and emulsification properties. Because the copolymers can form molecule micelle singlely, thus the level of reducing the surface tension and interfacial tension of PADB is limited. Because BEM has 22 long carbon chain, so PADB behave strong intramolecular hydrophobic associating behavior in aqueous solution; at the same time DMCPS has opposite charges, so PADB change from intramolecular association to intermolecular association under the addition of salt. In addition, when the polymer concentration is above 1.5g/L, the emulsion is oil-in-water type, PADB have good wettability and effect on viscosity of heavy oil emulsification.3. A series of hydrophobic modified partially hydrolyzed polyacrylamide PAAB were synthesised by the soap-free emulsion copolymerization of AM, sodium acrylate (NaAA) and BEM. The structures were characterized by IR,1H-NMR, and the aggregation behavior were studied by resonance scattering and dynamic light scattering. In addition, we broaden its application value through emulsification test. Results showed that heat resistance of PAAB is enhanced due to the introduction of the long chain hydrophobic monomer, at the same time a certain concentration of copolymer in aqueous solution can form association. Such hydrophobic modified polyacrylamide have good performance on emulsification, and have very good effect on reducing the viscosity of heavy oil. |
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