Hydration of synthetic polydialkylphosphate (PPF) — a simplified model for natural teichoic acids

The hydration of synthetic poly(P-hydroxy 1,3 propylenephosphate) in hydrogen and mixed H⁺-Mg⁺² forms has been studied by means of the pulsed NMR method. This polymer may be regarded as a simplified model of natural teichoic acids appearing in a cell wall of gram-positive bacteria. The investigations of nuclear magnetic relaxation of water protons in polymer gels prove the existence of two phases of water. One is water strongly bound to phosphate groups which does not freeze at low temperature and the other is weakly bound water freezing at 243–253 K. The distribution of correlation times has been stated for water in the first hydration shell of phosphate groups. For both acid and magnesium salt forms the hydration shell is composed of three water molecules.