NMR Study on Polymer‐Solvent Interactions during Temperature‐Induced Phase Separation in Aqueous Polymer Solutions

Some possibilities of NMR spectroscopy (mainly spin‐spin relaxation) in investigations of hydration and other polymer‐solvent interactions during the temperature‐induced phase separation in aqueous polymer solutions are described. A certain portion of water molecules bound in phase‐separated mesoglobules was revealed. The residence time of the bound HDO for poly(vinyl methyl ether) (PVME)/D 2 O solution ( c  = 6 wt%) is 1.2 ms. With time a slow release of originally bound water from the respective mesoglobules was observed. For highly concentrated PVME/D 2 O solutions ( c  = 20–60 wt%), the residence time of bound HDO ≫ 2.7 ms and fractions of bound water unchanged even for 70 h were found. A similar behaviour as described above for water (HDO) was also found for EtOH molecules in PVME/D 2 O/EtOH solutions.