Water-soluble polymers. 71. pH responsive behavior of terpolymers of sodium acrylate, acrylamide, and the zwitterionic monomer 4-(2-acrylamido-2-methylpropanedimethylammonio)butanoate

✍ Scribed by Erich E. Kathmann; Charles L. McCormick

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 835 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19970130)35:2<231::aid-pola5>3.0.co;2-v

✦ Synopsis

Terpolymers of sodium acrylate (NaA), acrylamide (AM), and the zwitterionic monomer 4-(2 -acrylamido-2-methy lpropanedimethylammonio) butanoate (AMPDAB) were prepared by the free radical polymerization in 0.5M NaBr aqueous solution using potassium persulfate as the initiator. The feed ratio of AMPDAB : NaA : AM was varied from 5:5:90 to 40: 40:20 mol %, with the total monomer concentration held constant at 0.45M. Terpolymer compositions were determined by l:]C NMR. Molecular weights varied from 3.0 X 106 to 9.7 X 10' g/mol. All terpolymers were soluble in deionized water and salt solutions at all pH values. The dilute and semidilute solution behavior of the terpolymers was studied as a function of composition, pH, and added electrolytes. Polyelectrolyte behavior was observed for all terpolymers at pH 8.5, as evidenced by high viscosity values at low polymer concentrations and viscosity decrease in the presence of added electrolytes. The reduced viscosity as a function of decreasing pH exhibits a minimum as the terpolymer undergoes a polyanion/ polyzwitterion/polycat ion transition. Comparison of the solution behavior of the terpolymers to terpolymers of 3-( 2-acrylamido-2-methylpropane dimethylammonio)-1-propane sulfonate (AMPDApS), AM, and NaA (AADAPS series) as well as copolymers of AMPDAB and AM (AMPDAB series) have been made. c l$IW.JohnWiley & Sons, Inc.