Behavior of Low Molecular Weight Model Heur Associative Polymers in Concentrated Surfactant Systems

The interaction between hydrophobically modified water-soluble polymers and surfactants has gained a growing interest in recent years. In this paper we present our results on the behavior of hydrophobically modified ethoxylate urethanes (HEUR) in concentrated surfactant systems, using an ethoxylated sulfate surfactant. The HEUR's differ in hydrophobic group, molecular weight, extent of modification, and polydispersity. As will be clear from our results the purification and characterization of these polymers are very difficult but also essential for the understanding of the characteristic behavior of these materials. Our experimental results from rheological experiments, phase-behavior, and flow birefringence are presented. Furthermore a mechanism describing the interaction between the surfactants and polymers will be discussed.