WATER IN METHACRYLATES .3. A CPPEMAS C-13-NMR STUDY OF THE EFFECT OF WATER ON GROUP MOTION IN POLY(2-HYDROXYETHYL METHACRYLATE) COPOLYMER NETWORKS

CPPEMAS C-13-NMR time-constants have been determined for poly(2-hydroxyethyl methacrylate-co-ethylene glycol dimethacrylate) networks in order to see the effect of increased cross-linking on the mobility of particular groups of the network and the effect of absorbed water. The results reflect the submicroscopic heterogeneity of the material which increases with increasing cross-link density. Water uptake appears to be directed by the prior and developing morphology rather than by chemical interaction.