Dielectric study on dynamics of water in polymer matrix using a frequency range 106–1010 Hz

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Abstract
Dielectric measurements were made on polyethylene glycol (PEG) and polyvinyl pyrolidone (PVP)–water systems over a frequency range 106 –1010 Hz by a time domain reflectometry. Two relaxation peaks were observed in the PVP system. The high frequency process is caused by rotational diffusion of water clusters and concentration dependence of the relaxation time is well explained by the free volume theory. The low frequency process is attributed to water molecules bound to the polymer and its relaxation time is reasonably irrespective of the concentration. On the other hand, the PEG system shows a single relaxation process which is caused by the rotational diffusion of water clusters. A sign of the segmental motion was recognized barely for highly concentrated system of PEG.