On Some Transition Phenomena in Aqueous Solution of Polyvinylalcohol

Abstract

In order to obtain an information about the configurational state of molecule in an aqueous solution of P.V.A., the measurements of the specific volume, the ultrasonic velocity and the dielectric constant were carried out over a certain range of the concentration and the temperature, and the experimental result was discussed from a view point of transition phenomena.
The result seems to show that in a region of concentration higher than a certain critical value (C_m) the configurational state of molecule in the solution is similar to that in solid P.V.A. plasticized by a solvent type plasticizer possessing no transition point, while in the region of concentration lower than C_m, only above a certain critical temperature T_β, a model of spherical coiled molecule is applicable. The heat of cross-linking estimated experimentally by making use of Eldridge and Ferry’s formula with respect to an apparent melting temperature of gel is about 12 k.cal./mol.