Self-assembly Networks of Anionic Hydrophobic Association Copolymer and Cationic Wormlike Micelles with Synergistic Viscosity Enhancement

A novel type of viscosity enhancement system composed of anionic hydrophobic association polyacrylamide P(NaAMC(14)S-b-AM) and cationic wormlike micelles, cetyltrimethylammonium bromide/sodium salicylate (CTAB/NaSal), was self-assembled in aqueous solution. The results of steady-state measurements and dynamic rheological experiments show that the self-assembly system has synergistic effects in aqueous solution at even 80 degrees C, and also its rheological behavior complies with Maxwell model. The rheological parameters, such as plateau modulus G(0), relaxation time tau(R) and the number density of entanglements nu, in the self-assembly system are all higher than those of the wormlike micelles. Therefore, it was suggested that the entangled networks between wormlike micelles and polymer chains be formed and also the hydrophobic "sticker" in copolymer chain embed into the core of wormlike micelles under both the hydrophobic association and electrostatic interactions.