Study on Association Behavior and Solution Properties of Poly(Acrylic Acid-Alkyl Polyoxyethylene Acrylate) Amphiphilic Copolymers

Abstract

The hydrophobically associating water-soluble polymers (HAWSPs), which possess both surfactant and polymer properties, have been the subject of considerable research. In this study, a novel HAWSP, poly(acrylic acid-alkyl polyoxyethylene acrylate) (P(AA-AAEOn)), was synthesized via aqueous polymerization of acrylic acid andalkyl polyoxyethylene acrylate (AAEOn) with different ethoxy groups. The structure of P(AA-AAEOn) was characterized by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). Additionally, its association behavior in solution was evaluated by surface tension, dynamic light scattering, and rheology. The results indicated that P(AA-AAEOn) exhibited excellent surface activity, and its ability to reduce the water surface tension increased with the increase in the proportion of the hydrophobic group. When the concentration reached 0.01%, P(AA-AAEOn) in the solution changed from intramolecular association to intermolecular association. Furthermore, P(AA-AAEOn) also displayed remarkable shear resistance, shear recovery, and viscoelasticity, with a transition from energy elasticity to entropy elasticity in P(AA-AAEOn) molecules between 25℃ and 35℃.