Properties of hydrophobically modified polyacrylamide with low molecular weight and interaction with surfactant in aqueous solution

Abstract

Hydrophobically modified polyacrylamide (HMPAM), with a molecular weight of 10 4 g/mol, was studied using a range of rheological methods and dynamic light scattering (DLS). DLS measurements indicate that the association of the modified polymer begins at low concentration. The modified polymer with high substitution forms transient networks below the critical concentration, but the networks are disrupted by the micelles formed by the polymer itself, and the networks do not contribute to viscosity enhancement. The modified polymers exhibited surface activity, and so they may be regarded as nonionic polymeric surfactants rather than thickeners. On the other hand, HM-PAM is shown to interact with the surfactant SDS while PAM is inert to SDS. In the hydrophobic domains, it undergoes a surfactant-induced association process; in the hydrophobe-surfactant transition regions, the surfactant binds to the polymer in a noncooperative way and forms a polymersurfactant complex. Contracted polymer chains begin to extend because of electrostatic repulsion, which can overcome the association at surfactant domains. The conformation of HMPAM polymer chains could be controlled by adding a specific amount of surfactant.

Network structure and mechanical properties of hydrophobic association hydrogels: Surfactant effect I

“…On the other hand, hydrophobically modified water-soluble polymers (HMWSP), consisting of a long hydrophilic backbone to which low amounts of hydrophobic constituents are attached, have been comprehensively researched in recent years. [12][13][14][15][16] Aqueous solutions of HMWSP always exhibit unusual rheological properties, due to the intermolecular reversible association of the hydrophobic groups. It is prone to form the mixed polymer/surfactant aggregations In the presence of ionic surfactants.…”

Hydrophobically Modified Sulfonated Polyacrylamides for IOR: Correlations between Associative Behavior and Injectivity in the Diluted Regime

“…Various techniques have been implemented among which viscosimetry [4][5][6][7][8][9][10][11][12], fluorescence [13][14][15][16], transmission, scanning and environmental scanning electron microscopy (TEM, SEM and ESEM) [16][17][18], 19 F NMR spectroscopy [19,20], neutron scattering [21][22][23][24] and Static and Dynamic Light Scattering (SLS and DLS) [14][15][16][25][26][27][28][29][30][31][32][33][34][35][36][37]. Theoretical approaches have also been proposed to describe HMWSP static [38,39] and dynamic [40] properties.…”

Libraries of modified polyacrylamides using post‐synthetic modification

“…Synthetic water-soluble polymers have been used for a number of years as viscosity enhancers in a broad number of industrial applications including paint formulations, foods, water purification, pharmaceuticals, cosmetics, drilling fluids, enhanced oil recovery, hydraulic fracturing and drag reducing agents. [1][2][3][4][5][6][7][8][9][10] Polymers based on acrylamide (PAM) are the most extensively studied group of synthetic water-soluble polymers so they are commercially available in large quantities. Despite the widespread use of PAM-based polymers they often exhibit a loss of performance when subjected to high temperatures, shear, or increasing ionic strength.…”