Self-assembly properties of a temperature- and salt-tolerant amphoteric hydrophobically associating polyacrylamide

Abstract

We prepared amphoteric hydrophobically associating polyacrylamides (AHAPAM) consisting mostly of hydrophilic polyacrylamide backbones, but also including the ionic hydrophobic monomer N,N-dimethyl octadeyl allyl ammonium chloride (DOAC) and the anionic monomer sodium 4-styrenesulfonate (SSS).The AHAPAM copolymer was prepared by carrying out aqueous solution polymerization. Macroscopic and microscopic self-assembly properties of AHAPAM in solution, as well as the effects of salt, temperature, and shearing on its association behavior were studied by carrying out viscosimetry, rheology, fluorescence spectroscopy (FS), and environmental scanning electron microscopy (ESEM) analyses. The results show that the association of the aqueous copolymer solutions were greatly affected by the concentration of the copolymer. The critical association concentration (CAC) of the AHAPAM solution was found to be 0.165 wt%, which was determined by carrying out viscometry and fluorescence spectroscopy experiments. Adding sodium chloride resulted in an increase in the apparent viscosity, which corresponded to the anti-polyelectrolyte solution behavior of AHAPAM. Meanwhile, intermolecular hydrophobic associations helped AHAPAM form a dynamic physically crosslinked network in its structure, conferring on AHAPAM strong heat-and shearing-resistance properties. The apparent viscosity of the 0.5 wt% copolymer solution was maintained at 92 mPa s at 140 C and 170 s À1 shearing for 1 h. FTIR and 1 H NMR spectra indicated the structure of the hydrophobically associating copolymers.And using the dilution extrapolation method, the intrinsic viscosity [h] of AHAPAM was shown to be 858.5 mL g À1 .

Assessment of Polyacrylamide Based Co-Polymers Enhanced by Functional Group Modifications with Regards to Salinity and Hardness

“…A similar explanation was reported for amphoteric hydrophobically associating polyacrylamide [42]. This kind of behavior in highly saline water makes the THERMOASSOCIATIF polymer more economical because a lower polymer consumption will be required to attain target viscosity for high salinity reservoir applications.…”

Adsorption–desorption behavior of the hydrophobically associating copolymer AM/APEG/C-18/SSS

“…Pyrene was weighed (30.3 mg), dissolved in methanol, transferred to a 150 mL clean volumetric ask, diluted with methanol to the scale, and prepared into a methanol solution of 1 mmol L À1 pyrene. The pyrene stock solution (0.04 mL, 1 Â 10 À3 mol L À1 in ethanol) was pipetted into a clean 5 mL volumetric ask with a micro sampler and the methanol was dried using nitrogen, aer the ethanol had been dried, the required amount of HPAAT and 20% HCl were dissolved in a volumetric ask and subjected to ultrasound for 0.5 h. 26 The HPAAT acid was placed at room temperature for 36 h as a backup. A uorescence spectrophotometer was used to scan the pyrene solution.…”

Polymeric and non‐crosslinked acid self‐thickening agent based on hydrophobically associating water‐soluble polymer during the acid rock reaction

“…Hydrophobically associating polymer is a special kind of polymer containing main chain macromolecules and a small amount of hydrophobic side chains, due to its excellent temperature resistance and salt resistance properties, which is widely used in oil and gas development, engineering materials, industrial coatings, sewage sludge, drug‐controlled release, and other fields …”