"Water Soluble Polymers. 76. Electrolyte Responsive Cyclocopolymers wit" by R. Scott Armentrout and Charles L. McCormick
 

Water Soluble Polymers. 76. Electrolyte Responsive Cyclocopolymers with Sulfobetaine Units Exhibiting Polyelectrolyte or Polyampholyte Behavior in Aqueous Media

Document Type

Article

Publication Date

1-25-2000

Department

Polymers and High Performance Materials

Abstract

Copolymers of N,N-diallyl-N,N-dimethylammonium chloride (DADMAC) and the zwitterionic monomer 3-(N,N-diallyl-N-methylammonio)propanesulfonate (DAMAPS) have been prepared in a 0.5 M NaCl aqueous solution using 2-hydroxy-1-[4-(hydroxyethoxy)phenyl]-2-methyl-1-propanone (Irgacure 2959) as the free-radical photoinitiator. The feed ratio of DADMAC:DAMAPS was varied from 100:0 to 0:100 mol % with the total monomer concentration held constant at 2.5 M. C-13 NMR data indicate that the resulting polymers maintain the five-membered ring structure in the cia conformation common to diallylammonium salts. Reactivity ratio studies indicate that the sulfobetaine monomer is incorporated randomly along the polymer backbone; Laser light scattering provided molecular weights and second virial coefficients, which varied from 5.16 x 10(4) to 8.42 x 10(4) and 5.54 x 10(-4) to 1.89 x 10(-4) mt mol g(-2), respectively. Solution behavior is dependent upon ionic strength as determined by low shear viscosity and dynamic light scattering experiments. For cyclocopolymers containing <40 mol % sulfobetaine, classical polyelectrolyte behavior is shown by viscosity decreases with increasing ionic strength. However, for polymers containing greater than or equal to 40 mol % sulfobetaine, chain expansion occurs as the ionic strength is increased above that required for the Donnan equilibrium.

Publication Title

Macromolecules

Volume

33

Issue

2

First Page

419

Last Page

424

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