Hydrogen bonding water with amorphous polymer

In summary, it has been observed that the hydrogen bonding interaction of water with amorphous polymers depends both on the chemistry of the polymer and to a lesser extent, on the changes in structural relaxation accompanying plasticization by water. In addition, the plasticizing effect of moisture produces other subtle effects on the polymer spectrum. 

In summary, it is clear that water absorbs into amorphous polymers to a significant extent. Interaction of water molecules with available sorption sites likely occurs via hydrogen bonding such that the mobility of the sorbed water is reduced and the thermodynamic state of this water is significantly altered relative to bulk water. Yet accessibility of the water to all potential sorption sites appears to be dependent on the previous history and physical-chemical properties of the solid. In this regard, the water-solid interaction in amorphous polymer systems is a dynamic relationship depending quite strongly on water activity and temperature. 

Fujita s model is valid for penetrant/polymer systems with diffusion coefficients that exhibit a strong concentration dependence, such as organic vapors in amorphous polymers, (20,22,24-27), but fails to describe the difference between water in poly(vinyl acetate) and in poly(methyl acrylate) (28). This may be due to the hydrogen-bonding nature of water rather than to a failure of the model. Fujita viewed his theory as inappropriate for small penetrant molecules, whose diffusion is largely independent of concentration, because the critical hole size for such penetrants is... 

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