Rheological properties of hydrophobically modified polyelectrolyte systems: Concentration effects

Abstract

The behavior of hydrophobically modified alkali‐soluble associative polymer (HASE) at various polymer concentrations was investigated. The results showed that the formation of network structure, which enhances the rheological behavior, depends on two critical polymer concentrations, namely the critical cluster overlapping concentration (C*) and the established network concentration (C**). C* is defined as the critical concentration for the transformation of individual cluster to a transient network structure. C** represents the critical concentration in the semidilute regime where the formation of transient network is completely established. Experimental results demonstrated that the polymer solutions transformed from a predominantly viscous behavior below C* to one with dominant elastic properties above C**. Because of the formation of larger aggregation number above C**, the relaxation times of the polymer systems shift to longer times. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5166–5173, 2006

Rheology of associative polymer solutions

“…Tam et al [118][119][120] superposed oscillatory shear and constant flow to probe the shear-induced structural changes of different HASE samples in the shear-thinning and shear-thickening regimes. They observed that with increasing applied stress, the junction density increased but the overall relaxation time of the system decreased.…”

Transient network topology of interconnected polyelectrolyte complex micelles

“…These associative thickeners are applied in paint formulations, cosmetics and oil recovery. Other telechelic polymers, [8][9][10][11][12] triblock copolymers 13,14 or other molecular architectures [15][16][17][18][19][20][21] are based on the same mechanism and driving force. Some of this work is summarized in a recent review by Tsitsilianis.…”

Achieving optimal micro-explosions in stable emulsions by adding water-soluble polymers

“…Therefore, NPAM has higher surface activity than XG. Similar to the concept of critical micelle concentration (CMC), the concentration of the lower inflection point in the σ-c isotherm, that is, the point of transition to the asymptote of minimum surface tension, is often referred to as the critical polymer concentration (CPC) or critical cluster overlapping concentration (C*) 43,44 . As seen in Figure . 6, the critical polymer concentrations of NPAM and XG are estimated to be 10 g/m 3 and 50 g/m 3 , respectively.…”