Title

Water-soluble polymers. 78. Viscosity and NRET fluorescence studies of pH-responsive twin-tailed associative terpolymers based on acrylic acid and methacrylamide

Document Type

Article

Publication Date

2-13-2001

Department

Polymers and High Performance Materials

Abstract

A series of terpolymers containing acrylic acid (AA), methacrylamide (MAM), and a twin-tailed hydrophobic monomer (DiC(6)AM, DiC(8)AM, or DiC(10)AM) were synthesized using micellar polymerization methods. These polymer systems were characterized using light scattering, viscometry, and fluorescence methods. Viscosity studies indicate that increasing the nonpolar character of the hydrophobic monomer (longer chain length or twin tailed vs single tailed) results in enhanced viscosity in aqueous solutions. The terpolymer with the highest hydrophobicity (MAM/AA/DiC(10)AM terpolymer) exhibited the most pronounced viscosity increase with polymer concentration and thus the best associative thickening. Fluorescence nonradiative energy transfer measurements performed on this terpolymer indicate the onset of association (c*) at a concentration of similar to0.1 g/dL. Also, changes in the energy transfer efficiency and viscosity behavior as a function of pH are consistent with a concentration-dependent transition from closed to open associations.

Publication Title

MACROMOLECULES

Volume

34

Issue

4

First Page

918

Last Page

924