Stimuli‐responsive ampholytic terpolymers of N‐acryloyl‐valine, acrylamide, and (3‐acrylamidopropyl)trimethylammonium chloride: Synthesis, characterization, and solution properties

Abstract

Low-charge density ampholytic terpolymers composed of acrylamide (AM), (3-acrylamidopropyl)trimethyl ammonium chloride (APTAC), and N-acryloylvaline were prepared via free-radical polymerization in 0.5 M NaCl to yield terpolymers with random charge distributions. Sodium formate (NaOOCH) was employed as a chain transfer agent during the polymerization to suppress gel effects and broadening of the molecular weight distribution (MWD). Terpolymer compositions were determined by 13 C NMR spectroscopy. Terpolymer molecular weights (MWs) and polydispersity indices (PDIs) were obtained via size exclusion chromatography/multi-angle laser light scattering (SEC-MALLS). Intrinsic viscosity values determined from SEC-MALLS data using the Flory-Fox relationship were compared with those determined by low-shear dilute solution viscometry and found to be in good agreement. SEC-MALLS experiments allowed examination of radius of gyration-MW (R g -M) relationships and the Mark-Houwink-Sakurada intrinsic viscosity-MW ([g]-M) relationships for terpolymers. The R g -M and [g]-M relationships indicated little or no excluded volume effects under SEC conditions indicating that the terpolymers were in near theta conditions in an aqueous buffer solution. Potentiometric titration experiments were performed in deionized (DI) water. These studies revealed that the apparent pK a of the AMVALTAC terpolymers increases with increasing VAL content. The solution properties of low-charge density ampholytic terpolymers have been studied as functions of solution pH, ionic strength, and polymer concentration. The charge-balanced terpolymers exhibit polyampholyte behavior at pH values ! 6.5. As solution pH is decreased, these charge-balanced terpolymers become increasingly cationic due to the protonation of the VAL repeat units. Charge-imbalanced terpolymers generally exhibit polyelectrolyte behavior, although the effects of intramolecular electrostatic interactions (e.g., polyampholyte effects) on the hydrodynamic volume are evident at certain values of solution pH and salt concentration. The solution behavior of the terpolymers in the dilute regime correlates well with that predicted by various polyampholyte solution theories.

Polyampholyte polymer as a stabiliser for subgrade soil

“…Further, the peaks at δ = 22. 40, 36.1, 42.67, 45.24, 52.93 and 64.08 ppm are ascribed to the aliphatic carbon signals of quaternary ammonium methyl, backbone methane, methylene and amide methylene, respectively (Kathmann et al 1994, Fevola et al 2004, Ezell et al 2006b). Compare Figures 9, 10 and 11 with Figure 13 and compare Figures 6, 7 and 8 with Figure 12.…”

Stimuli-Responsive Polymers and their Potential Applications in Oil-Gas Industry

“…18,[119][120][121][122][123][124] The first type stimuli-responsive polymer was designed to lower interfacial tension at oil/water interface, and thus forming the oil/water emulsification. The other synthesized molecular polymers have the prospective applications in modifying fluid viscosity and mobility during the oil recovery process.…”

Aqueous dispersion polymerization of amphoteric polyacrylamide

“…So, it has attracted considerable interests around the globe. [1][2][3] Until now, AmPAM has been prepared by four polymerization methods below: solution polymerization, [4][5][6] microemulsion polymerization, inverse microemulsion polymerization, 7 and dispersion polymerization. 8 Dispersion polymerization is a unique method due to its inherent simplicity of the single-step process in which particles ranged from 0.1 to 15 lm were formed.…”