Title

Water-Soluble Copolymers .63. Rheological and Photophysical Studies on the Associative Properties of Pyrene-Labeled Poly[acrylamide-co-sodium 11-(acrylamido)undecanoate]

Document Type

Article

Publication Date

7-17-1995

Department

Polymers and High Performance Materials

Abstract

The synthesis, theological, and fluorescence properties of a novel water-soluble polymer based on a micelle-forming monomer are reported. Sodium 11-(acrylamido)undecanoate (SA), a surface-active monomer, copolymerizes readily with acrylamide (AM) to give high molecular weight polymer. Incorporation of the fluorescent monomer [2-(1-pyrenylsulfonamido)ethyl]acrylamid into the monomer feed yields a terpolymer with associative solution properties different from previously synthesized AM/SA copolymers. The fluorescent label acts as a model hydrophobe; changes in associations that elicit a viscosity response in AM/SA copolymers also affect the emission characteristics of the pyrene label. Steady-significant fluorescence emission studies reveal significant constriction of the polymer chain as pH decreases or electrolyte concentration increases. As a result, the nature of pyrene-pyrene association can be varied from inter- to intramolecular as electrolyte or acid concentration increases. Fluorescence quenching studies indicate that the salt-induced chain contraction may enhance the organization of mixed polymeric micelles formed by SA and pyrene repeat units. Emission studies of mixed solutions of labeled AM/SA copolymer with surfactants reveal a micellar bridging mechanism. The steady-state emission techniques employed confirm the pronounced pH and salt-responsiveness of AM/SA-based polymers observed in viscosity studies.

Publication Title

Macromolecules

Volume

28

Issue

15

First Page

5248

Last Page

5254