Synthesis And Properties Of Hydrophobic Associating Water-soluble Copolymer Containing Sulfonate Structure

After several decades' development, water-soluble polymers have been used in many fields due to their excellent performance. But ordinary polyacrylamide (PAM) has a lack of anti-salt and anti-temperature. And there is limited technical path on how to increase the molecular weight, so experts are looking for new kinds of water-soluble polymers, one of those polymers called as hydrophobic associating water-soluble polymers which are brought in some associative compounds to increase the molecular weight to satisfy the need of anti-salt and anti-temperature.Sodium 2-acrylamido -2-methylpropanesulfonate (AMPSNa) is a very strong polar anion monomer which can increase the ability of the chain through resisting the attack from the external ions and it can enhance the hydration and the water solubility of the polymer. The three different hydrophobic monomers have their advantages respectively:α-methyl styrene (α-MSt) monomer has a phenyl ring which can increase the rigid of the polymer chain and has an excellent anti-temperature performance ;α-methyl octadecyl acrylate (α-MOcA) has a very long carbon chain which also shows the characterization of good associative property ,anti-salt and anti-temperature and perfluoro-hexyloxy-ethyl methacrylate (PFHEMA) is the monomer contains fluorine(F),because of the weak cohesive force of the C-F bond and the strong effect with the polar molecular, besides the electronegativity of F is very strong ,the chain is not easily fractured. All three monomers above can greatly enhance the stability of the polymer.In this experiment, the new anion hydrophobic associating polymers are synthesized by emulsion radical polymerization by changing the ratio of AM and AMPS, meanwhile fixing the amount of three different hydrophobic monomers under the conditions with the amount of initiator 0.5g at 70°C for 6 hours.Then the surface tension and viscosity of the three different copolymer solutions: acrylamide/sodium 2-acrylamido -2-methylpropanesulfonate /α-methyl styrene-4 (AM/AMPSNa/α-MSt-4),acrylamide/sodium2-acrylamido-2-methylpropanesulfonate/α-methyloctadecylacrylate-2(AM/AMPSNa/α-MOcA-2),acrylamide/sodium2-acryla mido-2-methylpropanesulfonate/perfluoro-hexyloxy-ethyl methacrylate-3 (AM/AMPSNa/PFHEMA-3) are discussed and find that surface tension is lower when adding the salt; And the viscosity decreased with the increase of the temperature, shear time and shear rate, but when adding the salt it performance the process decreased at first, then increased. AM/AMPSNa/α-MSt-4 has a good performance of anti-temperature as we thought. Though AM/AMPSNa/PFHEMA-3 has no phenyl ring but it still has a good performance of anti-temperature, anti-salt and anti-shear, according to the analysis, the hydrophobic monomer containing fluorine has shown a great application potential. The aggregation behavior are discussed by dynamic light scattering (DLS),the hydrodynamic radius of three polymers have a process increased at first and then decreased with the increase of the temperature, and have a performance that hydrodynamic radius decreased at first, then increased when adding the MgCl₂ and CaCl₂ salt solution.