Effect of Ca2+ on viscosity and microstructure of water‐soluble triblock terpolymer used as thicker in the hydraulic fracturing. Issue 20 (21st January 2019)

• Record Type: Journal Article
• Authors: Chen, Ruiyang; Wang, Shibin; Shen, Xin; Zhao, Feng; Guo, Jianchun
• Is Part Of: Journal of applied polymer science. Volume 136:Issue 20(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-01-21
• Subjects: calcium salt tolerance -- complexing -- polyacrylamide; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.47539
• Languages: English
• ISSNs: 0021-8995

Abstract

ABSTRACT: Ca 2+ tolerance of water‐soluble polyacrylamide is a key problem in application fields. It is urgent to make the mechanism of between the polyacrylamide and Ca 2+ clear. A terpolymer polyacrylamides including the sulfonate group with different monomer concentrations is synthesized. The effect of the CaCl2 concentration on the rheological properties is measured by a rheological rheometer. The zeta potential of the copolymer solution is obtained by a zeta potentiometer to learn about the electrical characteristics of the copolymers in solution. The microcosmic shape of the copolymer aqueous solution is investigated by a laser particle analyzer and an environmental scanning electron microscope. The results show that more sulfonate groups on the molecule can enhance the salt tolerance of the polyacrylamide. Sulfonate groups can weaken the effect of Ca 2+ on the copolymer through the formation of complexes, whereas the self‐aggregation process of the copolymer cannot be stopped at high Ca 2+ concentrations. This study provides theoretical guidance to elucidate the influencing rules and mechanism of calcium salt on the polyacrylamide containing a sulfonate group, which can be helpful for polyacrylamide modification and can improve the application of polyacrylamide under the condition of higher salt concentration. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019, 136, 47539. Abstract : Water‐soluble triblock terpolymer including sulfonate groups are synthesized by radical method on strict reaction conditions. The viscoelastic properties and microstructure at higher concentration of Ca 2+ of the polymer are investigated. Calcium ions affect the stretching or coiling of terpolymer chains through electrostatic interaction.