The influence of external conditions on the amount and properties of water in crosslinked hydrophilic polymers

Abstract

By optical volumetry (OVM) , dynamic desorption porosimetry (DCF) and isopiestic method
investigated the influence of the physical state of water on the amount and properties of water in gels of
hydrophilic polymers. The influence of the nature of the polymer chain, the polar group, the number and
nature of crosslinking agent on the properties of water in gels and the number of dissociating and
undissociating hydrophilic polymers analyzed. It is known that all polymers are swelling in the pair absorb
less water than the swelling in the liquid. DCF method shows that this excess water evaporates from the
polymer under the same conditions as the water on the exterior of the gel. That is swollen in water volume of
the polymer is water, not distinguishable in its properties from the external water. Found that the degree of
crosslinking and ionic form of the polar groups do not affect the amount of water penetrating further into the
polymer by placing its water. Based on this work concluded that the "swollen polymer - water" phase
interface is not the same as the visible boundary of swollen polymer and, hence, polymer gels should be
considered as two-phase system