An easy anion exchange between electrolyte monomers of the quaternary ammonium halide
type such as [(2-methacryloyloxy)ethyl]trimethylammonium chloride or 1-vinyl-3-methylimidazolium iodide
and various cyanocarbon salts such as 1,2,2-tricyanoethenolate, 1,1,2,3,3-pentacyanopropenide, α,α-dicyano-p-toluoylcyanide, or p-(tricyanovinyl)phenyldicyanomethide readily leads to a series of new
hydrophobic electrolyte monomers with yields generally over 70%. [(2-Methacryloyloxy)ethyl]trimethylammonium 1,1,2,3,3-pentacyanopropenide is a most representative example. Its free radical polymerization in homogeneous solution (DMF, 60 °C) currently yields atactic chains (Bernoulli stereopropagation
process, probability of meso placement P
m = 0.31) of fairly high degree of polymerization (DPw ∼ 1600)
which show an unique spectrum of solubility in dipolar organic solvents (dipole moment μ > 2.6 D) covering
a very broad range of dielectric constants (ε ∼ 10−180). Viscosity measurements performed in 13 solvents
allow us to analyze the polymer solution properties in three different situations: (a) For good, but weakly
dissociating solvent (triethyl phosphate, ε ∼ 10), there were no polyelectrolyte effects. (b) For good and
fairly to highly dissociating solvents (cyclopentanone...2-cyanopyridine, ε ∼ 13−90), as a general trend,
polyelectrolyte effects increase with the dielectric constant, but the usual excluded volume effects remain
a factor of the number of effective charges per chain, as estimated from the ratio A/B of the parameters
of the Fuoss equation in its simplified form (ηred = A/1 + BC
0.5). (c) For very poor but very strongly
dissociating solvents (formamide, N-methylformamide, ε > 100), there were no polyelectrolyte effects at
25 °C and transition to a fairly good solvent at about 50 °C with simultaneous emergence of weak
polyelectrolyte effects. These new hydrophobic polyelectrolytes appear as optimized and versatile models
for the quantitative analysis of the influence of the usual excluded volume effects and of the specific
electrostatic interactions on the static and dynamic solution properties of polyelectrolytes in all possible
solvation and dissociation situations.