Pulsed NMR studies of translational mobility of polymer molecules in polydialkylphosphate gels

The translational mobility of polypropylenephosphate (PPP) molecules has been studied by the NMR pulsed field gradient technique. The translational diffusion of long chain polymer molecules of polymerization degree ¯m > 20 may be neglected, in NMR measurements, on account of their rigidity. The self-diffusion coefficient of short chain polymer molecules (¯m=8) in PPP gels (¯D_s=3 · 10^–8 cm²/s) is about two orders of magnitude lower than that of water molecules in gels.Two hydrates, i. e. PPP(H⁺) · 3H₂O and PPP(H⁺, Mg²⁺) · 5H₂O represent the most stable structures, at temperature 293 K.