Water soluble copolymers: 38. Synthesis and characterization of electrolyte responsive terpolymers of acrylamide, N-(4-butyl)phenylacrylamide, and sodium acrylate, sodium-2-acrylamido-2-methylpropanesulphonate or sodium-3-acrylamido-3-methylbutanoate

Abstract

Responsive associative terpolymers of acrylamide, 0.5 mol% N-(4-butyl)phenylacrylamide and 5 and 25 mol% of one of the following: sodium acrylate, sodium-2-acrylamido-2-methylpropanesulphonate or sodium-3-acrylamido-3-methylbutanoate were synthesized by a micellar polymerization method. Terpolymer composition was determined by a combination of u.v. spectroscopy and elemental analysis. Solution properties were determined by low shear rheometry as functions of polymer concentration, solution ionic strength, pH and urea concentration. The carboxylate terpolymers exhibited high viscosities in the presence of up to 0.5 M NaCl and 0.17 M CaCl 2, but lose much of their viscosity at low pH and high urea content. The sulphonate-containing terpolymers are less responsive at low pH and high electrolyte concentration than the carboxylate-containing terpolymers.