THERMODYNAMICS OF THE INTERACTION BETWEEN TETRAZOLE-CONTAINING POLYELECTROLYTES AND WATER

Thermodynamics of the interaction between tetrazole-containing polyele ctrolytes and water was studied at 298 K. The Gibbs free energies, ent halpies, and entropies of mixing are negative for the dissolution and swelling of poly(C-vinyltetrazoles) in water. For un-ionized polyacids the plots of the enthalpies of dilution (mixing) for un-ionized polya cids versus the composition of polymer-water system exhibit additional extrema at a water content 10-20%. This fact is explained by the ''or dering'' and the ''disorderings'' effects of water. The affinity of po ly(C-vinyltetrazoles) to water is significantly enhanced on ionization of the polymers considered. The changes in the thermodynamic paramete rs of polymer dissolution depend on the conformational state of macrom olecules, which is determined by their hydrophilic-hydrophobic balance .