Abstract
When water passes through a polymer gel, a frictional resistance arises between the water and the polymer network of gel. If the network is permanently crosslinked, it is natural to assume that the friction, normalized by the viscosity of water, shouid be independent of temperature. We found, however, that the friction decreases reversibly by three orders of magnitude and appears to diminish as the gel approaches a certain temperature, This phenomenon occurs in spite of the fact that the network structure and the total volume of the gel, thus the average density of the network, are unchanged.
